A retort or vessel used for distillation by the method of descent.
Late Middle English; earliest use found in Geoffrey Chaucer (c1340–1400), poet and administrator. Apparently from (i) Anglo-Norman descensorie, dessensorie.
Relating to or of the nature of distillation by descent; (of a furnace) used for such distillation.
Early 17th century; earliest use found in John Woodall (1570–1643), surgeon. From post-classical Latin descensorius descending, used for distillation by descent from classical Latin dēscēns-, past participial stem of dēscendere + -ōrius.