S: (n) situation, state of affairs (the general state of things; the combination of circumstances at a given time) "the present international situation is dangerous"; "wondered how such a state of affairs had come about"; "eternal truths will be neither true nor eternal unless they have fresh meaning for every new social situation"- Franklin D.Roosevelt
S: (n) challenge (a call to engage in a contest or fight)
S: (n) challenge (questioning a statement and demanding an explanation) "his challenge of the assumption that Japan is still our enemy"
S: (n) challenge (a formal objection to the selection of a particular person as a juror)
S: (n) challenge (a demand by a sentry for a password or identification)
S: (n) requisition (the act of requiring; an authoritative request or demand, especially by a military or public authority that takes something over (usually temporarily) for military or public use)
S: (n) call (a demand for a show of hands in a card game) "after two raises there was a call"
S: (n) margin call, call (a demand by a broker that a customer deposit enough to bring his margin up to the minimum requirement)
S: (n) wage claim, pay claim (the wage demanded from management for workers by their union representatives)