VIREO
vireo
(noun) any of various small insectivorous American birds chiefly olive-grey in color
Source: WordNet® 3.1
Etymology
Noun
vireo (plural vireos or vireoes)
Any of a number of small insectivorous passerine birds, of the genus Vireo, that have grey-green plumage.
Any bird of the family Vireonidae, which includes vireos, shrike-vireo, greenlets and peppershrikes.
(in plural) The family Vireonidae.
Usage notes
The alternative plural form vireoes appears to be relatively rare and dated.
Source: Wiktionary
Vir"e*o, n. Etym: [L., a species of bird.] (Zoöl.)
Definition: Any one of numerous species of American singing birds belonging
to Vireo and allied genera of the family Vireonidæ. In many of the
species the back is greenish, or olive-colored. Called also greenlet.
Note: In the Eastern United States the most common species are the
white-eyed vireo (Vireo Noveboracensis), the redeyed vireo (V.
olivaceus), the blue-headed, or solitary, vireo (V. solitarius), the
warbling vireo (V. gilvus), and the yellow-throated vireo (V.
flavifrons). All these are noted for the sweetness of their songs.
Source: Webster’s Unabridged Dictionary 1913 Edition