Descant

Part of speech: noun (n.)

1. Originally, a double song; a melody or counterpoint sung above the plain song of the tenor; a variation of an air; a variation by ornament of the main subject or plain song.

2. The upper voice in part music.

3. The canto, cantus, or soprano voice; the treble. Grove. Twenty doctors expound one text twenty ways, as children make descant upon plain song. Tyndale. She [the nightingale] all night long her amorous descant sung. Milton.

4. A discourse formed on its theme, like variations on a musical air; a comment or comments. Upon that simplest of themes how magnificent a descant! De Quincey.

Part of speech: verb (v.)

1. To sing a variation or accomplishment.

2. To comment freely; to discourse with fullness and particularity; to discourse at large. A virtuous man should be pleased to find people descanting on his actions. Addison.