① 主要な部分。② ある句を構成する語または句で、その句の中心的な意味と文法上の役割を決めるもの。
main parts; main components
primary business; primary function; primary focus
major newspaper; leading newspaper; widely circulated newspaper
primary factor; main cause
key customers; key customer; major clients; major client
major histocompatibility complex; MHC
prices of staple commodities
essential elements of information