adverse witness adverse witness /ˈædvɜːrs ˈwɪtnəs/

noun

1. A witness whose relationship to the opposing party is such that his or her testimony may be prejudiced against the opposing party  ( adverse witness , hostile 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
   a hostile witness can be asked leading questions and cross-examined