Goatee
Hair grown on the chin only, sometimes with a moustache, so named after a billy goat's tuft.
Also: chin beard
A goatee is a small beard on the chin, without the cheeks. Strictly it is the chin tuft alone; a goatee joined to a moustache in a ring is often called a circle beard. Barbers suggest goatees to lengthen a round face or add weight to a narrow chin. The goatee was popular among 1950s jazz musicians and again in the 1990s. It needs regular trimming to keep its outline.