Etymology
Borrowed from Brazilian Portuguese guariba, from Old Tupi gûariba. Other early European spellings/renderings of the same Tupian word include guariva, guariha, uariba, waariba, and in French ouarive/ouariue (which was misread as ouarine, giving rise to that word and, by anglicization of it, to warine). The Century Dictionary suggests a possible relation to araguato and/or araba (an obsolete word for a howler monkey of the genus Mycetes); the New English Dictionary directs readers to compare alouatte and araguato.
Definitions & examples from Wiktionary (CC BY-SA 3.0).