Definition of sit out:
(v) :
(ambitransitive) To decline to participate; particularly, to decline to dance.
(v) :
(transitive) To await the cessation of, without taking part.
(v) :
(poker) To be away from the table in the midst of an ongoing game, thus automatically placing one's forced bets and otherwise folding every hand when it is one's time to act.
(v) :
(wrestling) To escape a hold while face down by swinging one's legs around into the sitting position.
(v) :
(nautical) To lean out to the windward side of a sailboat in order to counterbalance the effects of the wind on the sails.
(n) :
Alternative form of sitout. [(chiefly India, Nigeria) An outdoor area that is set up for sitting, including a floor and seats, and possibly, but not necessarily having a roof, screens, or elevated platform.]