- l. (Zool.) One of numerous species of small American
singing birds, of the genus Vireo, as the solitary, or blue-headed
(Vireo solitarius); the brotherly-love (V. Philadelphicus); the
warbling greenlet (V. gilvus); the yellow-throated greenlet (V.
flavifrons) and others. See Vireo. - Any species of Cyclorhis, a genus of tropical American
birds allied to the tits.