n. (pl. -ies) 1 the state of being three. 2 a group of three. 3 (the Trinity or Holy Trinity) Theol. the three persons of the Christian Godhead (Father, Son, and Holy Spirit). Trinity Brethren the members of Trinity House. Trinity House Brit. an association concerned with the licensing of pilots, the erection and maintenance of buoys, lighthouses, etc., in England, Wales, etc. Trinity Sunday the next Sunday after Whit Sunday. Trinity term Brit. the university and law term beginning after Easter.
[ ME f. OF trinité f. L trinitas -tatis triad (as TRINE) ]