[ yoo-nuh-lat-er-uhl ]
See synonyms for unilateral on Thesaurus.com
  1. relating to, occurring on, or involving one side only: unilateral development; a unilateral approach.

  2. undertaken or done by or on behalf of one side, party, or faction only; not mutual: a unilateral decision; unilateral disarmament.

  1. having only one side or surface; without a reverse side or inside, as a Möbius strip.

  2. Law.

    • pertaining to a contract that can be formed only when the party to whom an offer is made renders the performance for which the offeror bargains.

    • pertaining to a contract in which obligation rests on only one party, as a binding promise to make a gift.

  3. Botany. having all the parts disposed on one side of an axis, as an inflorescence.

  4. through forebears of one sex only, as through either the mother's or father's line.: Compare bilateral (def. 5).

  5. Phonetics. (of an l-sound) characterized by passage of air on only one side of the tongue.

Origin of unilateral

From the New Latin word ūnilaterālis, dating back to 1795–1805. See uni-, lateral

Other words from unilateral

  • u·ni·lat·er·al·i·ty [yoo-nuh-lat-uh-ral-i-tee], /ˌyu nəˌlæt əˈræl ɪ ti/, noun
  • u·ni·lat·er·al·ly, adverb

Words Nearby unilateral

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use unilateral in a sentence

British Dictionary definitions for unilateral


/ (ˌjuːnɪˈlætərəl) /

  1. of, having, affecting, or occurring on only one side

  2. involving or performed by only one party of several: unilateral disarmament

  1. law (of contracts, obligations, etc) made by, affecting, or binding one party only and not involving the other party in reciprocal obligations

  2. botany having or designating parts situated or turned to one side of an axis

  3. sociol relating to or tracing the line of descent through ancestors of one sex only: Compare bilateral (def. 5)

  4. phonetics denoting an (l) sound produced on one side of the tongue only

Derived forms of unilateral

  • unilateralism or unilaterality, noun
  • unilaterally, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012