prefix

American  

[pree-fiks, pree-fiks, pree-fiks] / ˈpri fɪks, ˈpri fɪks, priˈfɪks /

noun

• prefixes
  plural

1. Grammar. an affix placed before a word, base, or another prefix to modify a term's meaning, as by making the term negative, as un- in unkind, by signaling repetition, as re- in reinvent, or by indicating support, as pro- in proabolition. Compatible prefixes can work together, as un- and re- in unrefundable.

2. something prefixed, as a title before a person's name.

   She uses the prefix “Ms.” rather than "Mrs."

---

verb (used with object)

• prefixes,
  present (3rd person singular)
• prefixed,
  past participle,  past
• prefixing
  present participle

1. to fix or put before or in front.

   to prefix an impressive title to one's name.

2. Grammar. to add as a prefix.

3. to fix, settle, or determine beforehand.

   If you call a taxi, the rate to the airport will be prefixed.

4. Biology. to apply the first of two fixatives to.

prefix British  

/ priːˈfɪks-, priːˈfɪkʃən, ˈpriːfɪksəl /

noun

1. grammar an affix that precedes the stem to which it is attached, as for example un- in unhappy Compare suffix

2. something coming or placed before

---

verb

1. to put or place before

2. grammar to add (a morpheme) as a prefix to the beginning of a word

prefix Cultural  

1. Letters placed in front of a word to form a new word: “tri monthly,” “semi monthly,” “bi lingual,” “multi lingual,” “ad dress,” “re dress,” “pre date,” “post date.” (Compare suffix.)

---

Grammar

A prefix is one kind of affix. An affix is an element that, although not a word itself, can be bound to a word, or to the base or stem of a word, to form a derivative with a related meaning. Entire families of related words can be derived from an existing word in this way. Although linguists sometimes divide the subject more finely, there are essentially three kinds of affix —the prefix, attached to the beginning (as un- in unconscious ), the infix, inserted in the middle, and the suffix, tacked on at the end (as -ness, in consciousness ). Note the lack of an example for infix. Standard English—unlike some other languages—does not use infixes, unless we count isolated instances of tmesis, where instead of an affix, an entire word is inserted, as in the playful “abso-bloomin'-lutely” in the lyrics of “Wouldn't It Be Loverly?”—a song from the musical My Fair Lady. (“Bloomin'” is probably a euphemism; other tmetic insertions are more often than not obscene.) But one-shot nonce words such as “abso-bloomin'-lutely” are neither added to the language nor found in standard dictionaries of English. On the other hand, both prefixes and suffixes are highly productive derivational forms, constantly in use to form new English words. A few of the most productive English prefixes are anti-, non-, pre-, re-, sub-, and un-. They are so common that some print dictionaries show simple lists, without definitions, of words that have been formed with them—taking it for granted that their meanings are obvious. Here at Dictionary.com, however, such terms, when not given entries and definitions of their own, are shown with other related forms at the bottom of the entry for the word on which the derivative is based. Thus a query for unacetic will take you automatically to acetic, helping you to understand your queried word without having to look up its bits and pieces separately. The grammatical term prefix itself has the prefix pre-; in this case, pre- means “before; preceding” and one meaning of fix is “to attach or place.” A word can have more than one prefix, like un- and re- in unremarkable. And a prefix can be used in combination with one or more suffixes. A simple example is reactivate, which has the prefix re- “again” added to the verb activate. Activate, in turn, is composed of the adjective active “engaged in action” and the suffix -ate, used to form verbs. Activate means “to make something active; cause it to function.” To reactivate is to do this again. But we must exercise some care in our analysis of words that are new to us; a casual glance at word formations may be deceptive. For example, to capitulate is “to surrender.” But recapitulate does not mean “to surrender again.” It means “to summarize.” In addition, some prefixes have more than one meaning. For example, if you look up un- in Dictionary.com, you'll find two entries. The first, un- ¹, means “not” (as in unafraid and unsettled ), the second, un- ², reverses the meaning of the verb it is attached to, as in unzip or in the social media term unfriend. But the most common problem with words formed with prefixes is determining whether or not to hyphenate between the prefix and the base word. Luckily, there are some guidelines. In general, there is no hyphen ( nonstarter, postcranial, unemployment, antievolution ). However, hyphenating is mandatory when the prefix is followed by a capital letter ( anti-Nazi, pre-Columbian ). We also hyphenate when a prefix that ends in a or i precedes a word starting with the same letter ( ultra-abysmal, anti-inflation ). However, words formed with prefixes ending in e or o followed by the same letter are in a state of flux ( cooperate and co-operate are variants, as are preeminent and pre-eminent ), but the solid form is increasingly more frequent. At the same time, certain words must be hyphenated to avoid ambiguity or misreading. re-sign (to sign again) is different from resign (to give up an office or position), and re-ink (to apply ink again) would look like some strange one-syllable word if spelled reink. But the easiest rule to remember may be this: when you are not sure whether to hyphenate a particular word, it is best to look it up.

Usage

What is a prefix? A prefix is a type of affix that appears at the beginning of a word and modifies its meaning, such as the re- in redo. An affix is a word element that is added to the base of a word to create a new word. A prefix comes at the beginning of the word. Some of the most common prefixes are ones that change a word with a positive meaning into one with a negative meaning, such as un-, in-, and dis-. For example, when we add un- to acceptable, we get the word unacceptable, which means not acceptable. When attaching a prefix to a word, the spelling of the original word doesn’t change, even if it creates a double letter, as in irreplaceable and preexist. However, words that would have a double a or i are often hyphenated, as in ultra-aware and anti-inflammatory. When we add a prefix to a capitalized word, we also use a hyphen, as in pre-Rome and non-French. The prefixes self- and ex- (meaning former) also use hyphens, as in self-interest and ex-wife. Finally, hyphens are used to prevent confusion if a prefix would cause a word to resemble another word with a different meaning. For example, re-tread means to tread again, while retread means to put a new tread on a tire.

Other Word Forms

Derived Forms

• prefixion
  noun
• prefixable
  adjective
• prefixal
  adjective
• unprefixal
  adjective
• unprefixed
  adjective
• prefixally
  adverb
• unprefixally
  adverb

Inflected Forms

Nouns

• prefixes
  plural

Participles

• prefixing
  present
• prefixed
  past

Conjugated Forms

Present

• prefix
  simple
• prefixes
  simple
• have prefixed
  perfect
• has prefixed
  perfect
• am prefixing
  progressive
• are prefixing
  progressive
• is prefixing
  progressive
• have been prefixing
  perfect progressive
• has been prefixing
  perfect progressive

Past

• prefixed
  simple
• had prefixed
  perfect
• was prefixing
  progressive
• were prefixing
  progressive
• had been prefixing
  perfect progressive

Future

• will prefix
  simple
• will have prefixed
  perfect
• will be prefixing
  progressive
• will have been prefixing
  perfect progressive

Etymology

Origin of prefix

First recorded in 1375–1425 for verb; 1640–50 for noun; late Middle English verb prefixen, prefyxe, from Middle French prefixer, from Latin praefixus, past participle of praefīgere “to set up in front”; English noun praefix, prefix, from New Latin praefixum, neuter of praefixus; see pre-, fix

Explanation

A prefix is affix that's added in front of a word and often changes the meaning of it. Common prefixes include re-, un-, and mis-. Lots of words have a prefix, and it's sometimes easier to figure out the meaning of those words if you know the meaning of the prefix. For example, the super- means "above" or "over"; hypo- and infra- mean "under." Prefix itself has a prefix: pre-, which means "before." In fact, the Latin root of prefix is praefixus, meaning "fixed in front." (Note our word's opposite here, suffix, which describes what is fixed at the back of a word.)

Example Sentences

See Examples For:

prefix prefixes prefixed prefixing

One number, with a 901 prefix from Shelby County, Tenn., jumped out, Sternin testified, because of the number of times that Harvey had contacted it.

From Los Angeles Times ● Aug. 5, 2026

That prefix would also have to remind the AI to obey the laws of physics with wording like: “gravity and inertia respected—mass has real weight, correct contact shadows, no floating props.”

From The Wall Street Journal ● May 21, 2026

The name, a play on the prefix in the region and Trump’s names, started as a joke.

From Salon ● Apr. 30, 2026

When the first system of motor vehicle registration was introduced in the 1900s, a one or two letter prefix was followed by a number with up to four digits.

From BBC ● Jan. 5, 2025

The prefix un was a later addition, and eventually the final I on the old “untill” fell off.

From "Woe Is I" by Patricia T. O'Conner

The Paris and Geneva families settled their dispute in 2018, agreeing to add prefixes or additional names in marketing.

From The Wall Street Journal ● Apr. 30, 2026

The conference handed out call-letter prefixes — C for Canada, X for Mexico, F for France, and so on.

From Los Angeles Times ● Aug. 12, 2024

“It is a very difficult word,” Haviv said, veering gracefully around the pileup of prefixes that Congress chose to describe the 250th anniversary of American independence — fast approaching on July 4, 2026.

From Seattle Times ● Dec. 4, 2023

To boost comprehension, students learn about prefixes, root words and suffixes — for example that “bene” means good or “audi” means hear.

From New York Times ● Dec. 25, 2022

The prefixes may help you remember: en means “in” or “within”; epi means “upon” or “close to”; pan means “all.” farther/further.

From "Woe Is I" by Patricia T. O'Conner

But the 26-year-old American does not take too kindly to the words 'self-proclaimed' being prefixed to her 'Greatest Woman of All Time' alias.

From BBC ● Feb. 4, 2022

Basic Care has a large Amazon logo right at the top, Stone and Beam notes that its products are “exclusively on Amazon,” and Rivet’s product names are prefixed with “Amazon Brand.”

From The Verge ● Nov. 30, 2021

Other Lamonts married descendants of the Plymouth Puritan William Bradford, Ned’s grandfather prefixed by nine “greats.”

From Salon ● Nov. 28, 2018

Once upon a time, more or less every team had one, the relevant player’s name usually prefixed by “diminutive” and “Scot”; Tony Green, for example.

From The Guardian ● May 29, 2015

When prefixed to the name of an office, ex- denotes that the person formerly held the office named: as, ex-mayor, the former mayor.

From New Word-Analysis by William Swinton

The ubiquity of “Design” has rendered itself in many forms, prefixing and suffixing subjects including graphic, product, industrial, computer, systems, architecture, community, environments, molecules, and more.

From Forbes ● Oct. 10, 2012

Ever since Hollywood started prefixing adaptations of the Bard's work with "William Shakespeare's", authorial provenance has inflicted some unsightly vandalism on film titles.

From The Guardian ● May 8, 2010

In fact, any game may be termed a rig, racket, suit, slum, etc. by prefixing thereto the particular branch of depredation or fraud in question.

From Time Magazine Archive

Gunzh is the radix for plant; Tig for tree; Asee for animal, &c.; and either by suffixing or prefixing syllabical increments, the terminology of the three great departments of nature is formed.

From Algic Researches, Comprising Inquiries Respecting the Mental Characteristics of the North American Indians, Vol. 1 of 2 Indian Tales and Legends by Henry Rowe Schoolcraft

To make the decasyllabic verse, the poet takes the liberty of prefixing to the present participle the y which properly belongs only to the past.

From Minor Poems by Milton by John Milton