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

Peters was found guilty in August on seven counts convicting her for assisting in facilitating unauthorized access to voting equipment after the 2020 election, aiming to bolster Trump’s claim the election results were illegitimate. —Alex Gangitano, The Hill, 6 May 2025

Nothing in the court’s opinion, however, required states to create voucher programs, much less implied that reserving public education funds for public schools was illegitimate. —Derek W. Black, The Conversation, 6 May 2025

Every American should reject the president's and his cronies' illegitimate use of government power to attack his enemies. —Thomas G. Moukawsher, MSNBC Newsweek, 17 Apr. 2025

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