When a lawyer cross-examines someone during a trial or hearing, he or she questions them about the evidence that they have already given. The accused's lawyers will get a chance to cross-examine him You know you are liable to be cross-examined mercilessly about the assault. + cross-examination cross-examinations cross-examination during the cross-examination of a witness in a murder case Under cross-examination, he admitted the state troopers used more destructive ammunition than usual. to ask someone questions about something that they have just said, to see if they are telling the truth, especially in a court of law