How to Write 吲 (yǐn) — Meaning “smile (archaic); used in chemical terms”

Picture a mouth (口) being pulled (引) into a wide smile. The right part 引 looks like a person drawing a smile upward. This visual of 'pulling a smile' helps link the character to its old meaning.

Write the left radical 口 first (three strokes: vertical, horizontal fold, horizontal), then the right side 引 (four strokes: horizontal fold, horizontal, vertical, vertical fold hook). A common mistake is making the right hook too sharp; it should be a gentle curve. Keep the left mouth small and aligned with the top of 引.

The key difference is the right side: 吲 has 引 which includes a vertical hook at the bottom right. 卟 has 卜 (a downward stroke) on the right, while 古 has 十 (ten) under the mouth. Remember that 吲's hook is like a 'pull' shape, whereas the others lack that hook.

Today, 吲 is almost never used alone with its ancient meaning 'smile'. Instead, it appears in scientific terms like 吲哚 (yǐn duǒ, indole), a compound found in flowers and coal tar. You'll encounter it in chemistry, biology, or fragrance industry contexts.

Common words containing 吲 include: 吲哚 (yǐn duǒ) — indole; 吲哚类 (yǐn duǒ lèi) — indoles; 吲哚环 (yǐn duǒ huán) — indole ring.