gibbonPronunciation: /ˈgɪb(ə)n/Definition of gibbon noun a small, slender tree-dwelling ape with long powerful arms and loud hooting calls, native to the forests of SE Asia. Family Hylobatidae and genus Hylobates: several species Origin: late 18th century: from French, from an Indian dialect wordgibbon in other Oxford dictionaries Definition of gibbon in the US English dictionary