tr.v. con·firmed, con·firm·ing, con·firms
a. To support or establish the certainty or validity of; verify: confirm a rumor.
b. To reaffirm the establishment of (a reservation or advance arrangement).
2. To make firmer; strengthen: Working on the campaign confirmed her intention to go into politics.
3. To make valid or binding by a formal or legal act; ratify.
4. To administer the religious rite of confirmation to.
[Middle English confirmen, from Old French confermer, from Latin cōnfirmāre : com-, intensive pref.; see COM- + firmāre, to strengthen (from firmus, strong; see dher- in the Appendix of Indo-European roots).]
con·firma·to′ry (-fûrmə-tôr′ē) adj.
Synonyms: confirm, corroborate, substantiate, authenticate, validate, verify
These verbs mean to establish or support the truth, accuracy, or genuineness of something. Confirm implies the establishment of certainty or conviction: The information confirmed our worst suspicions.
To corroborate something is to strengthen or uphold the evidence that supports it: The witness is expected to corroborate the plaintiff's testimony.
To substantiate is to establish by presenting solid or reliable evidence: "What I shall say can be substantiated by the sworn testimony of witnesses" (Mark Twain).
To authenticate something is to establish its genuineness, as by expert testimony or documentary proof: Never purchase an antique before it has been authenticated.
Validate refers to establishing the validity of something, such as a theory, claim, or judgment: The divorce validated my parents' original objection to the marriage.
Verify implies proving by comparison with an original or with established fact: The bank refused to cash the check until the signature was verified.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2016 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus