stage manager

from The Century Dictionary.

• noun In theaters, one who superintends the production and performance or a play, and who regulates all matters behind the curtain.

from the GNU version of the Collaborative International Dictionary of English.

• (Theat.) One in control of the stage during the production of a play. He directs the stage hands, property man, etc., has charge of all details behind the curtain, except the acting, and has a general oversight of the actors. Sometimes he is also the stage director.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A person responsible for the organization of a stage production, and who is in charge of the stage during the performance

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun someone who supervises the physical aspects in the production of a show and who is in charge of the stage when the show is being performed