fre.num

n.（名詞）
【復數】 fre.nums 或 fre.na [-n…] 【解剖學】
A membranous fold of skin or mucous membrane that supports or restricts the movement of a part or organ, such as the small band of tissue that connects the underside of the tongue to the floor of the mouth.
系褶：皮膚的一種膜狀褶或粘膜用來支持或限制某部位或器官的運動，例如連接舌下部和口腔底部的一小段組織

來源：
Latin frônum [bridle]
拉丁語 frônum [韁繩]
from frendere [to grind] * see ghrendh-
源自 frendere [碾磨] *參見 ghrendh-