from
The Collaborative International Dictionary of English v.0.48
Yuen \Yu"en\, n. (Zool.)
The crowned gibbon ({Hylobates pileatus}), native of Siam,
Southern China, and the Island of Hainan. It is entirely
arboreal in its habits, and has very long arms. the males are
dark brown or blackish, with a caplike mass of long dark
hair, and usually with a white band around the face. The
females are yellowish white, with a dark spot on the breast
and another on the crown. Called also {wooyen}, and {wooyen
ape}.
[1913 Webster]