trisect

t. [Lat. tri =three, and sect us, pa par. of seco =to cut.] To cut or divide into three equal parts. "Could I not by adding water, have bisected or trisected a drop."-De Quincey: Opium-eater, p. 129. tri-sěct'-ěd, pa . par . or a . [TRISECT.] 1. Ord. Lang .: (See the verb.) 2. Bot .: Trifid; tri parted (q. v.).