To make a declaration of truth or fact under oath; submit testimony: witnesses testifying before a grand jury.
To express or declare a strong belief, especially to make a declaration of faith.
To make a statement based on personal knowledge in support of an asserted fact; bear witness: the exhilaration of weightlessness, to which many astronauts have testified.
To serve as evidence: wreckage that testifies to the ferocity of the storm.
To declare publicly; make known: testifying their faith.
To state or affirm under oath: testified in court that he saw the defendant.
To bear witness to; provide evidence for. See Synonyms at indicate.