fingernail

She painted her fingernails bright red to match her evening dress.

(Chinese) 她把指甲涂成了鲜红色，以搭配她的晚礼服。

Biting your fingernails is often a nervous habit that people develop during childhood.

(Chinese) 咬指甲通常是人们在童年时期养成的一种紧张习惯。