Webster's Revised Unabridged Dictionary · 1913

Guenon

Guenon , noun

[French]

(Zoology) Any of several long-tailed arboreal African monkeys, of the genera Cercopithecus and Erythrocebus (formerly classified as Cercocebus), such as as the green monkey (Cercopithecus callitrichus) and grivet (Cercopithecus griseo-viridis).