uni

Uni- is a combining form used like a prefix, meaning “one.”  Uni- appears in a wide variety of everyday and technical terms alike.

Uni- comes from the Latin ūnus, meaning “one.” The Greek counterpart of uni- is mono-, as in monologue. Learn more at our Words That Use article on the form.

One popular word that features uni- is unicorn, “a mythical creature resembling a horse, with a single horn in the center of its forehead.” The word comes from the Latin ūnicornis, which uses the equivalent form uni- in the language.

If uni- means “one,” what does the -corn portion of the word signify? The element -corn refers to “horn,” from the Latin cōrnu. Unicorn literally translates to “(having) one horn.”

What are some words that use the combining form uni-?

• unialgal
• uniaxial
• unibrow
• unicycle
• unicuspid
• unicameral
• unicellular
• unidimensional
• unidirectional
• unifacial
• unifilar
• uniflorous
• unifoliate
• uniglandular
• unilinear
• unilingual
• unilocular
• unimodal
• uniplanar
• unipolar
• unipotent
• unisex
• unispiral
• uniseptate
• univariate

The following words use the equivalent forms of uni- in Latin:

• uniform
• unijugate
• uniparous
• universe
• university

What are some other forms that uni- may be commonly confused with?

• in-
• omni-
• un-

Not every word that begins with the letters uni- is necessarily using the combining form uni- to mean “one.” These words, such as unidentified, are instead using the form un-, “not,” in combination with a second form beginning with the letter i. Learn more about the word unidentified at our entry.

The word cycle, from Greek kýklos, has a variety of meanings, including “wheel.” With this in mind, what does unicycle mean?