Entry 2 senses · 2 variants Webster, 1913 Tretis · Tre·tis · IPA n. a. 01 n. A treatise; also, a treaty. 1. A treatise; also, a treaty.[Obs.] 02 a. Long and well-proportioned; nicely made; pretty. 1. Long and well-proportioned; nicely made; pretty.[Obs.]