illegitimate

adjective

il·​le·​git·​i·​mate ˌi-li-ˈji-tə-mət 

1

a

: not recognized as lawful offspring

b

: born of parents not married to each other

2

a

: not sanctioned by law : illegal

b

: not authorized by good usage

c

of a taxon : published but not in accordance with the rules of the relevant international code

3

: not rightly deduced or inferred : illogical

4

: departing from the regular : erratic

illegitimately adverb

Synonyms

• baseborn
• misbegotten
• natural
• spurious
• supposititious
• unfathered

Examples of illegitimate in a Sentence

She thinks that my concerns are illegitimate.

They were fired from their jobs for illegitimate reasons.

Recent Examples on the Web

His failure to win the popular vote made his election feel contestable, even illegitimate. —Gal Beckerman, The Atlantic, 5 Apr. 2025

Among them, pyramid schemes, membership fee fakes, credit repair cons, dubious health offers, fictitious diploma schools and illegitimate gaming services. —Charles Selle, Chicago Tribune, 2 Apr. 2025

Created primarily to fight organized crime, RICO was seldom used until a 1981 Supreme Court decision expanded its interpretation to apply to both legitimate and illegitimate enterprises, according to Jeffrey Grell, an expert on the law who previewed the case for the American Bar Association. —Maureen Groppe, USA Today, 2 Apr. 2025

Above all, Garcia welcomed the rare opportunity to be a part of a Latine family that is financially comfortable without being involved in anything illegitimate. —Brian Davids, HollywoodReporter, 27 Mar. 2025

Word History

First Known Use

1536, in the meaning defined at sense 1a

Rhymes for illegitimate

• legitimate

Kids Definition

illegitimate

adjective

il·​le·​git·​i·​mate ˌil-i-ˈjit-ə-mət 

1

: born of a father and mother who are not married

2

: illegal

illegitimately adverb

Legal Definition

illegitimate

adjective

il·​le·​git·​i·​mate ˌi-li-ˈji-tə-mət 

1

: not recognized by the law as offspring

specifically : born out of marriage

Note: An illegitimate child is usually legitimated by his or her parents' later marriage. Illegitimate children generally have the same inheritance rights under intestate successions as legitimate children; statutes limiting their inheritance rights have been found to violate the equal protection clause.

2

: not valid according to law

illegitimate noun