a cast other than the principals
"The critics praised the entire ensemble for their energetic supporting roles, even though they were not the main stars."
the chorus of a ballet company
"The entire ensemble performed the grand finale to thunderous applause from the audience."
an assemblage of parts or details (as in a work of art) considered as forming a whole
"The architect praised the building's ensemble, noting how every window and brick worked together to form a perfect whole."
a coordinated outfit (set of clothing)
"She arrived at the gala wearing an elegant black ensemble that included a tailored jacket and silk trousers."
A group of separate things that contribute to a coordinated whole.
"The team's success relied on an ensemble of diverse skills working together toward a common goal."
In plain English: An ensemble is a group of people who perform together as part of a show, movie, or musical production.
"The entire musical ensemble performed flawlessly during the concert tonight."
Usage: Use the noun form when referring to a matching set of clothing or a musical group, and use the verb form only for actions involving coordination. Avoid confusing it with "ensemble" as an adjective; instead, describe items as being part of an ensemble or wearing them in an ensemble manner if needed.
To put together in a coordinated whole.
"The director carefully selected each costume to ensure they would blend seamlessly into an ensemble that perfectly matched the film's aesthetic."
In plain English: To ensemble means to put different things together as a single group.
"The team will ensemble for the final performance next week to ensure perfect harmony."
The word entered English directly from French, where it originally meant "all together." It retained its sense of a group performing or working as one unit when adopted into the English language.