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

However, illegitimate reviews can be particularly problematic within fintechs, wherein such reviews can attract scrutiny and prompt regulatory investigations, thereby causing significant time and cost spent to resolve such scrutiny. —Branden Abushanab, Forbes, 14 Mar. 2025

Trump has repeatedly -- and falsely -- framed his Ukrainian counterpart as an illegitimate leader and Ukraine as the instigator of Russia's war. —David Brennan, ABC News, 9 Mar. 2025

Mir, who works for his father’s legitimate business, completely unaware of the illegitimate one, is the smaller, more compact, more driven brother. —Robert Lloyd, Los Angeles Times, 5 Mar. 2025

In 1776, when King George tried to seize illegitimate control over the colonists by taxing them without their consent, the citizenry launched the American Revolutionary War. —David McGrath, Chicago Tribune, 3 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