An Ensemble

1. A group of separate things that contribute to a coordinated whole.
2. (fashion) A coordinated costume or outfit; a suit.
3. (collective) A group of musicians, dancers, actors, etc who perform together; e.g. the chorus of a ballet company.
4. (music) A piece for several instrumentalists or vocalists.
5. (mathematics, physics) A probability distribution for the state of the system.
6. (machine learning) A supervised learning algorithm combining multiple hypotheses.