testify

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To make a declaration of truth or fact under oath; submit testimony: witnesses testifying before a grand jury.
2. v. To express or declare a strong belief, especially to make a declaration of faith.
3. v. 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.
4. v. To serve as evidence: wreckage that testifies to the ferocity of the storm.
5. v. To declare publicly; make known: testifying their faith.
6. v. To state or affirm under oath: testified in court that he saw the defendant.
7. v. To bear witness to; provide evidence for. See Synonyms at indicate.

Century Dictionary and Cyclopedia

1. To bear witness; make declaration, especially for the purpose of communicating to others a knowledge of some matter not known to them, or for the purpose of establishing some fact.
2. In law, to give testimony, under oath or solemn affirmation, in a cause depending before a court.
3. To serve as evidence; be testimony or proof.
4. To bear witness to; affirm or declare as fact or truth.
5. In law, to state or declare under oath or affirmation, as a witness, before a tribunal.
6. To give evidence of; evince; demonstrate; show.
7. To make known; publish or declare freely.

Wiktionary

1. v. to make a declaration, or give evidence, under oath
2. v. to make a statement based on personal knowledge or faith

GNU Webster's 1913

1. v. To make a solemn declaration, verbal or written, to establish some fact; to give testimony for the purpose of communicating to others a knowledge of something not known to them.
2. v. To make a solemn declaration under oath or affirmation, for the purpose of establishing, or making proof of, some fact to a court; to give testimony in a cause depending before a tribunal.
3. v. To declare a charge; to protest; to give information; to bear witness; -- with against.
4. v. To bear witness to; to support the truth of by testimony; to affirm or declare solemny.
5. v. To affirm or declare under oath or affirmation before a tribunal, in order to prove some fact.
6. adv. In a testy manner; fretfully; peevishly; with petulance.

WordNet 3.0

1. v. give testimony in a court of law
2. v. provide evidence for