informal

American  

[in-fawr-muhl] / ɪnˈfɔr məl /

adjective

1. without formality or ceremony; casual.

   an informal visit.

   Synonyms:

   easy, natural

2. not according to the prescribed, official, or customary way or manner; irregular; unofficial.

   informal proceedings.

   Synonyms:

   unconventional

   Antonyms:

   conventional

3. suitable to or characteristic of casual and familiar, but educated, speech or writing.

4. Grammar. characterizing the second singular pronominal or verbal form, or its use, in certain languages.

   the informal[hasp] tu in French.

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informal British  

/ ɪnˈfɔːməl /

adjective

1. not of a formal, official, or stiffly conventional nature

   an informal luncheon

2. appropriate to everyday life or use

   informal clothes

3. denoting or characterized by idiom, vocabulary, etc, appropriate to everyday conversational language rather than to formal written language

4. denoting a second-person pronoun in some languages used when the addressee is regarded as a friend or social inferior

   In French the pronoun "tu" is informal, while "vous" is formal

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Usage

The label Informal is used in this dictionary to mark terms that are not likely to occur in serious, prepared speech or carefully edited writing except when used intentionally to convey a casual tone. But under what circumstances is informal English apropos, appropriate, A-OK, even bitchen? What exactly is informal English? And how does it differ from slang, which is even more unlikely to occur in formal speech or edited writing? Most sources agree that informal English typically avoids long, complex sentences, features a liberal use of contractions and other casual terms, and—in speech—allows elided pronunciations like gonna for going to . The particular words and phrases that dictionaries label Informal tend to be short, metaphorical, and somewhat out of place in carefully edited, serious prose. They include terms like abs, carbs, guys, big shot, spill the beans, and knock it off. Familiar, intimate, and unpretentious, in relaxed circumstances informal English is the frequent choice of a wide range of users, including educated speakers. Dictionaries do not apply special labels to terms that occur in the most neutral variety of the language, which is so much the norm that we tend not to notice it. Nor do they label formal terms. Habitual users of English, however, are aware of different levels of formality. For example, in ordinary, neutral English we might say that people are worried or nervous. More formally, they are apprehensive, disquieted, or beset by misgivings. Informally, they may be antsy, in a lather, or spooked. And in slang, they can be uptight, wired, or bummed out. In the second sentence of this note, apropos is formal, appropriate is neutral, and A-OK is informal. At the other end of the linguistic spectrum from the formal apropos is the slang term bitchen, meaning “marvelous” or “wonderful.” In effect, informal English is English that is not quite neutral but not quite slang. Slang is very informal, and its environment is often restricted, in that some of its terms are associated with a profession (military slang), a period of time (jazz-age slang), a group or subculture (teen slang), or an interest or activity (computer slang). Slang is characteristically metaphorical ( airhead for “a scatterbrained person”), playful ( canoodle for “to pet; fondle amorously”), elliptical ( bro for “brother”), vivid ( coffin nail for “a cigarette”), and ephemeral ( cat's pajamas, 1920s slang for “something wonderful”). Some slang is vulgar. Slang terms rarely occur in formal, prepared speech or in edited writing. Informal language, on the other hand, has recently seeped into situations that once mandated careful, formal speech. For some, this is a welcome development. But not everyone is pleased; complaints are sometimes heard when people think that a speaker in some relatively formal situation, trying to be folksy, has come across as insufficiently professional, professorial, or even presidential. But although dictionaries categorize levels of linguistic formality on the basis of extensive observation of actual language use, the boundaries between these levels are flexible and porous. English as a widely spoken language is especially fluid and ever changing. Unlike some languages, it is not subject to dicta by a supervisory or regulating body. Throughout the history of English, some words in its lexicon have moved up from one category to another and then another—sometimes quickly, sometimes over centuries. The word snide, “nastily derogatory,” was once slang, as were tip, “a gratuity paid for service,” and frame, “to incriminate with false evidence.” In fact, slang terms that catch on broadly and firmly enough to remain in common use beyond one generation can generally be said to have outgrown their Slang label. Movement in the other direction, from neutral to slang, is far more rare. One classic example is bastard. Its literal sense, “a person born of unmarried parents,” first appeared in the late thirteenth century, almost two centuries before such an individual could be referred to as illegitimate. The current slang senses, “a despicable person” or just “a person” ( The poor bastard broke his leg ), did not emerge until the early to mid nineteenth century. Unlike words whose status moves from slang through informal to neutral, all the while retaining their original meanings, standard words that move the other way and become slang tend to do so by adding a new, usually metaphorical, sense. Not all dictionaries agree when categorizing words and phrases on a sociolinguistic scale. These decisions are difficult to make. A word or definition labeled Slang in one dictionary but Informal in another may be unlabeled in a third. And yet, whatever guidance one finds in a reputable dictionary is usually sufficient. Most of us can judge when to vary our language. Consciously or unconsciously, we choose language appropriate to each communicative setting. And much of the time, a dash of informality is just … dandy.

Related Words

See colloquial.

Other Word Forms

• informally adverb
• quasi-informal adjective
• superinformal adjective

Etymology

Origin of informal

First recorded in 1595–1605; in- ³ + formal ¹

Explanation

If something’s informal, it’s casual and relaxed and doesn’t follow any particular rules or conventions, whether that's a style of writing, or the dress code for your dinner party. If you have informal plans to see your friend, that means you’ll get together but you’re not sure when — you’ll figure it out later. Informal also means “casual,” like wearing jeans and a t-shirt. Informal writing or speech is the linguistic equivalent of wearing jeans and a t-shirt, with a relaxed tone and simple words. In an informal football club, you don't pay dues to anyone, you just show up at the park and play with whoever is there.

Example Sentences

The industry - which is largely informal - supplies firecrackers for weddings, festivals and other ceremonies and has faced repeated scrutiny over safety standards.

From BBC • Apr. 22, 2026

I had an informal meeting with him in the UK recently and I asked him then whether he really was heir apparent to the Apple throne.

From BBC • Apr. 21, 2026

If anything, Coop studies people, studies groups of folks and systems, and how informal and formal systems of specific societies interact.

From Los Angeles Times • Apr. 13, 2026

Think of it as an informal meeting that lasts several hours.

From The Wall Street Journal • Apr. 9, 2026

My new teammates called out their names as I gave each of them a quick dap, an informal greeting of clasped hands and bumped chests.

From "The Other Wes Moore: One Name, Two Fates" by Wes Moore

Related Words

• colloquial
• conversational
• familiar
• vernacular