verb (used with object), in·val·i·dat·ed, in·val·i·dat·ing.

to render invalid; discredit.
to deprive of legal force or efficacy; nullify.

Origin of invalidate

First recorded in 1640–50; invalid2 + -ate1
Related formsin·val·i·da·tion, nounin·val·i·da·tor, noun

Synonyms for invalidate Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for invalidate

Contemporary Examples of invalidate

Historical Examples of invalidate

British Dictionary definitions for invalidate


verb (tr)

to render weak or ineffective, as an argument
to take away the legal force or effectiveness of; annul, as a contract
Derived Formsinvalidation, nouninvalidator, noun
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 invalidate

1640s, from invalid + -ate (2). Related: Invalidated; invalidating.

Online Etymology Dictionary, © 2010 Douglas Harper