唇 means “lips”

くちびる · kuchibiru

Kun'yomi (Japanese reading)
くちびる
On'yomi (Chinese reading)
シン

JLPT N1 · Taught in secondary school · 10 strokes

The story

A mouth (口) under 辰, often explained as a clam with its shell open: soft lips parting. 唇 is the lips: 唇を噛む is biting your lip in frustration, and 唇が荒れる is lips chapped by the dry Japanese winter.

Used in 唇 (kuchibiru, lips), 上唇 (uwakuchibiru, upper lip), and 下唇 (shitakuchibiru, lower lip)

More from Head to Toe

Learn 唇 and more kanji free on Fuji Learning · All kanji

Readings from KANJIDIC2, © EDRDG, CC BY-SA.