that does not stop holding something or give up something easily; determined 紧握的；不松手的；坚持的 continuing to exist, have influence, etc. for longer than you might expect 顽强的；坚忍不拔的 a tenacious illness 顽症
Word Originearly 17th cent.: from Latin tenax, tenac- (from tenere ‘to hold’) + -ious.