[ tes-tuh-fahy ]
See synonyms for: testifytestifier on Thesaurus.com

verb (used without object),tes·ti·fied, tes·ti·fy·ing.
  1. to bear witness; give or afford evidence.

  2. Law. to give testimony under oath or solemn affirmation, usually in court.

  1. to make solemn declaration.

verb (used with object),tes·ti·fied, tes·ti·fy·ing.
  1. to bear witness to; affirm as fact or truth; attest.

  2. to give or afford evidence of in any manner.

  1. Law. to state or declare under oath or affirmation, usually in court.

  2. to declare, profess, or acknowledge openly.

Origin of testify

1350–1400; Middle English testifyen<Latin testificārī to bear witness, equivalent to testi(s) witness + -ficārī-fy

Other words for testify

Other words from testify

  • tes·ti·fi·er, noun
  • pre·tes·ti·fy, verb (used with object), pre·tes·ti·fied, pre·tes·ti·fy·ing.
  • re·tes·ti·fy, verb, re·tes·ti·fied, re·tes·ti·fy·ing.
  • un·tes·ti·fy·ing, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use testify in a sentence

British Dictionary definitions for testify


/ (ˈtɛstɪˌfaɪ) /

verb-fies, -fying or -fied
  1. (when tr, may take a clause as object) to state (something) formally as a declaration of fact: I testify that I know nothing about him

  2. law to declare or give (evidence) under oath, esp in court

  1. (when intr, often foll by to) to be evidence (of); serve as witness (to): the money testified to his good faith

  2. (tr) to declare or acknowledge openly

Origin of testify

C14: from Latin testificārī, from testis witness

Derived forms of testify

  • testification, noun
  • testifier, 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