[adjective, noun il-i-jit-uh-mit; verb il-i-jit-uh-meyt]



a person recognized or looked upon as illegitimate.

verb (used with object), il·le·git·i·mat·ed, il·le·git·i·mat·ing.

to declare illegitimate.

Origin of illegitimate

First recorded in 1530–40; il-2 + legitimate
Related formsil·le·git·i·mate·ly, adverbil·le·git·i·mate·ness, il·le·git·i·ma·tion, noun

Synonyms for illegitimate

2, 3. See illegal. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for illegitimate

Contemporary Examples of illegitimate

Historical Examples of illegitimate

  • Who he is no one exactly knows; some say an illegitimate son of Beckendorff.

    Vivian Grey

    Earl of Beaconsfield, Benjamin Disraeli

  • The fate of illegitimate children who are "farmed out" is still worse.

  • Girls who have illegitimate children often lose their situations and their honor.

  • I am haunted by the thought of that illegitimate child of my husband's.


    Emile Zola

  • The Latin is illegitimate; and he infers that, therefore, the English is the same.

    The Verbalist

    Thomas Embly Osmun, (AKA Alfred Ayres)

British Dictionary definitions for illegitimate



born of parents who were not married to each other at the time of birth; bastard
forbidden by law; illegal; unlawful
contrary to logic; incorrectly reasoned


an illegitimate person; bastard
Derived Formsillegitimacy or illegitimateness, nounillegitimately, 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

Word Origin and History for illegitimate

1530s, "born out of wedlock," formed in English (and replacing earlier illegitime, c.1500), modeled on Latin illegitimus "not legitimate" (see il- + legitimate). Sense of "unauthorized, unwarranted" is from 1640s. Phrase illegitimi non carborundum, usually "translated" as "don't let the bastards grind you down," is fake Latin (by 1965, said to date from c.1939) (Carborundum was a brand of abrasives).

Online Etymology Dictionary, © 2010 Douglas Harper