annul

verb an·nul \ə-ˈnəl\

: to say officially that something is no longer valid : to make (something) legally void

an·nulledan·nul·ling

Full Definition of ANNUL

transitive verb

: to reduce to nothing : obliterate

: to make ineffective or inoperative : neutralize <annul the drug's effect>

: to declare or make legally invalid or void <wants the marriage annulled>

See annul defined for English-language learners

See annul defined for kids

Origin of ANNUL

Middle English annullen, from Anglo-French annuller, from Late Latin annullare, from Latin ad- + nullus not any — more at null

First Known Use: 15th century

Related to ANNUL

Synonyms: offset, cancel (out), compensate (for), correct, counteract, counterbalance, counterpoise, make up (for), negative, neutralize

Synonym Discussion of ANNUL

nullify, negate, annul, abrogate, invalidate mean to deprive of effective or continued existence. nullify implies counteracting completely the force, effectiveness, or value of something <a penalty nullified the touchdown>. negate implies the destruction or canceling out of each of two things by the other <the arguments negate each other>. annul suggests making ineffective or nonexistent often by legal or official action <the treaty annuls all previous agreements>. abrogate is like annul but more definitely implies a legal or official act <a law to abrogate trading privileges>. invalidate implies making something powerless or unacceptable by declaration of its logical or moral or legal unsoundness <the court invalidated the statute>.