protected by trademark or patent or copyright; made or produced or distributed by one having exclusive rights; "`Tylenol' is a proprietary drug of which `acetaminophen' is the generic form"
something that serves as a preceding event or introduces what follows; "training is a necessary preliminary to employment"; "drinks were the overture to dinner"
a minor match preceding the main event
designed to orient or acquaint with a situation before proceeding; "a preliminary investigation"