noun
Refers to the lower jaw or chin area. In everyday use, context distinguishes between the whole jaw structure and the chin specifically.
彼は転んで顎を打った。
He fell and hit his chin.
あごが疲れるまでガムを噛んだ。
I chewed gum until my jaw got tired.
noun
The small backward-pointing projection on a fishhook that keeps the hook from slipping out. Often used in fishing contexts.
この釣り針にはあごが付いていない。
This fishhook doesn't have a barb.