臭い
くさい · kusai · JLPT N3 · i-adj
stinky
🦨 臭 = 自 nose + 犬 dog (now 大): what a dog sniffs out is kusai, stinky
自 first meant nose; people point at their nose to say me. The old form of 臭 had 犬 dog under it, a dog's nose, so the character first meant smell. In Japanese 臭い (kusai) means a bad smell, and -臭い on a word means smelling of it.
臭 — 自 (nose) + 犬 (dog)
Originally a pictograph combining 自 (nose) and 犬 (dog), depicting a dog using its nose to sniff out scents. The early meaning was 'to smell,' later extended to 'odor' and then narrowed to 'foul smell.' The 'smell/sniff' sense was preserved in the later character 嗅.