Word:

# Problem

Prob´lem
n.1.
1.A question proposed for solution; a matter stated for examination or proof; hence, a matter difficult of solution or settlement; a doubtful case; a question involving doubt.
2.(Math.) Anything which is required to be done; as, in geometry, to bisect a line, to draw a perpendicular; or, in algebra, to find an unknown quantity.
 Plane problem (Geom.) a problem that can be solved by the use of the rule and compass.
 Solid problem (Geom.) a problem requiring in its geometric solution the use of a conic section or higher curve.
 Noun 1 problem - a state of difficulty that needs to be resolved; "she and her husband are having problems"; "it is always a job to contact him"; "urban problems such as traffic congestion and smog"Synonyms: job 2 problem - a source of difficulty; "one trouble after another delayed the job"; "what's the problem?"Synonyms: trouble 3 problem - a question raised for consideration or solution; "our homework consisted of ten problems to solve"