noun
A small pointed beard on the chin, resembling a goat's beard.
彼はやぎひげを生やしている。
He has a goatee.
やぎひげが似合う人もいる。
Some people look good with a goatee.
あごひげ is a general term for a beard on the chin, while やぎひげ specifically refers to a goatee style.
Compound of 山羊 (やぎ, 'goat') and ひげ ('beard'), referring to the resemblance to a goat's chin beard.