Definitions for vireoˈvɪr iˌoʊ
Random House Webster's College Dictionary
any of various small, insectivorous, typically dull-plumaged songbirds of the family Vireonidae, of the New World, having a slightly hooked bill.
Origin of vireo:
1825–35; < NL; L vireō (Pliny), prob. the greenfinch, der. of virēre to be green
any of various small insectivorous American birds chiefly olive-grey in color
Any of several small insectivorous passerine birds, of the genus Vireo, that have grey-green plumage
any one of numerous species of American singing birds belonging to Vireo and allied genera of the family Vireonidae. In many of the species the back is greenish, or olive-colored. Called also greenlet