禁煙
きんえん · kinen · JLPT N3 · noun
smoke
🚬 禁煙 = forbid (禁 kin) + smoke (煙 en): smoke is forbidden
禁 (kin) means forbid, as in 禁止 kinshi, prohibition. 煙 (en) is smoke; note the fire radical 火 on its left. Put together, kin + en = smoking forbidden, the word on no-smoking signs across Japan.