hostile witness(n = noun.person) adverse witness - a witness whose relationship to the opposing party is such that his or her testimony may be prejudiced against the opposing party; "a hostile witness can be asked leading questions and cross-examined"
is a kind of witness

N  evidence, facts, premises, data, praecognita, grounds, indication, criterion, testimony, testification, expert testimony, attestation, deposition, examination, admission, authority, warrant, credential, diploma, voucher, certificate, doquet, docket, testamur, record, document, pi ce justificative, deed, warranty, signature, seal, exhibit, material evidence, objective evidence, witness, indicator, hostile witness, eyewitness, earwitness, material witness, state's evidence, deponent, sponsor, cojuror, oral evidence, documentary evidence, hearsay evidence, external evidence, extrinsic evidence, internal evidence, intrinsic evidence, circumstantial evidence, cumulative evidence, ex parte evidence, presumptive evidence, collateral evidence, constructive evidence, proof, evidence in chief, secondary evidence, confirmation, corroboration, support, ratification, authentication, compurgation, wager of law, comprobation, citation, reference, legal research, literature search (experiment), showing, indicative, indicatory, deducible, grounded on, founded on, based on, corroborative, confirmatory, by inference, according to, witness, a fortiori, still more, still less, raison de plus, in corroboration, of, valeat quantum, under seal, under one's hand and seal, dictum de dicto, mise en evidence.

adverse witness, bear witness, bear witness against, bearing false witness, character witness, expert witness, false witness, hostile, hostile expedition, hostile fire, hostile takeover, jehovah's witness, lay witness, material witness, witness, witness box, witness stand