Merriam-Webster's Collegiate® Dictionary, 11th Edition
UPSTAGE
I. adverb
Date: 1870
toward or at the rear of a theatrical stage, away from a motion-picture or television camera,
II. adjective
Date: 1918
haughty , of or relating to the rear of a stage,
III. transitive verb
Date: 1921
to draw attention away from , to force (an actor) to face away from the audience by staying upstage, to treat snobbishly,
IV. noun
Date: circa 1931
the part of a stage that is farthest from the audience or camera