Of birds: To produce tuneful or musical sounds; to warble.

intransitive. Of a bird: to make characteristic melodious whistling and twittering sounds.

Chiefly of a songbird. intransitive. To sing, warble. Obsolete.

intransitive. To warble, to quaver in singing.

intransitive. Of birds: To sing clearly and sweetly.

intransitive. Of a songbird: to utter a brief phrase of song. Obsolete.

intransitive. Of birds: To make a similar noise.

intransitive. Of a songbird: to sound a note with a trill. Cf. roll, n.2 4b. Obsolete. rare.