1. A melody that is sung or played higher than the main melody of a piece of music.
2. An ornamental melody or counterpoint sung or played above a theme; or the highest part sung in a musical part.
3. A lengthy discourse on a subject: "The politician tended to make descants that were too long and complicated; when a shorter, to-the-point, answer to questions from the audience would be much more acceptable."
4. Etymology: from about 1380, from Anglo-French deschaunt; from Medieval Latin (as written and spoken about 700 to 1500) discantus, "a refrain, part-song"; from Latin dis-, "asunder, apart" + cantus, "song" from the past participle of canere, "to sing".

The spelling was partly Latinized in the 16th century. It originally meant, "counterpoint"; the sense of "talk at length" was first recognized in 1649.