An adverse witness refers to a witness who intentionally gives unfavorable evidence against the party that called him or her as its witness.. An adverse witness’s testimony is biased against the examining party. Adverse witness can be asked leading questions during direct examination and also be cross-examined. The party calling the witness can direct the attention of adverse party to his/her early statement. The party can contradict the witness by other evidence also.
An adverse witness is also called a hostile witness.