n.1 a a thing viewed as the sum of its parts. b the general effect of this.
2 a set of clothes worn together; an outfit.
3 a group of actors, dancers, musicians, etc., performing together, esp. subsidiary dancers in ballet etc.
4 Mus. a a concerted passage for an ensemble. b the manner in which this is performed (good ensemble).
5 Math. a group of systems with the same constitution but possibly in different states.
Etymology: F, ult. f. L insimul (as IN-(2), simul at the same time)