What is indicated when testimony is classified as 'adverse witness'?

When testimony is classified as from an 'adverse witness,' it means that the witness's statements or evidence are detrimental to the interests of the party that called them to testify. This classification implies that the witness is not supportive of the case for which they were called, but rather, their testimony may undermine that party's position or credibility. For example, if a plaintiff calls a witness but the witness provides information that harms the plaintiff's arguments or supports the defendant's claims, then that witness is considered adverse. This distinction is important in legal contexts, as it affects how testimony is perceived and handled during proceedings.