culet

n. 多面体宝石的底面

cu.let

n.（名词）
The small flat face at the bottom of a gem cut as a brilliant.
宝石座：以多角形琢磨法切割而成的宝石的底部小平面
Armor consisting of overlapping plates used to protect the buttocks.
护臀甲：由相互交迭的甲片构成的铠甲，用来保护臀部

来源：
Obsolete French [diminutive of] cul [rump]
已废法语 [] cul的小后缀 [臀部]
from Latin côlus * see (s)keu-
源自 拉丁语 côlus *参见 (s)keu-