\Where*in"\, adv. 1. In which; in which place, thing, time, respect, or the like; -- used relatively. Her clothes wherein she was clad. --Chaucer. There are times wherein a man ought to be cautious as well as innocent. --Swift. 2. In what; -- used interrogatively. Yet ye say, Wherein have we wearied him! --Mal. ii. 17.