主しゅ要よう納のう入にゅう先さきMeaningsNoun1. key customers; key customer; major clients; major clientKanji used主(one's) master要needed納to supply入enter先before (timewise)Composed of主しゅ要ようchief; main; principal; majorNa-adjective納のう入にゅうpayment (of taxes, fees, etc.); supply (of goods); deliveryNoun先さきpoint; tip; end; nozzle; head (of a line); front; first; before; ahead (of); (the way) ahead; …Noun