descant

[Cacasenno]

descant

SYLLABICATION: des·cant
PRONUNCIATION: dsknt
NOUN: 1. also dis·cant (ds-) Music a. An ornamental melody or counterpoint sung or played above a theme. b. The highest part sung in part music. 2. A discussion or discourse on a theme.
INTRANSITIVE VERB: Inflected forms: des·cant·ed, des·cant·ing, des·cants
(dsknt, d-sknt)1. To comment at length; discourse: “He used to descant critically on the dishes which had been at table” (James Boswell). 2. also dis·cant ( dsknt, d-sknt) Music a. To sing or play a descant. b. To sing melodiously.
ETYMOLOGY: Middle English, from Anglo-Norman descaunt, from Medieval Latin discantus, a refrain : Latin dis-, dis- + Latin cantus, song, from past participle of canere, to sing. See kan- in Appendix I.
OTHER FORMS: descanter —NOUN

The American Heritage® Dictionary of the English Language: Fourth Edition. 2000

Is this meaning entirely obsolete?

[Faerthurin]

Well, I've never heard that use.