三分裂的
三剖面的

Trisect \Tri*sect"\, v. t. [imp. & p. p. {Trisected}; p. pr. &
vb. n. {Trisecting}.] [Pref. tri- + L. sectus, p. p. of
secare to cut. See {Section}.]
1. To cut or divide into three parts.

2. (Geom.) To cut or divide into three equal parts.


Trisected \Tri*sect"ed\, a. (Bot.)
Divided into three parts or segments by incisions extending
to the midrib or to the base; -- said of leaves.