marked by qualities giving the power to produce an intended effect; "written propaganda is less efficacious than the habits and prejudices...of the readers"-Aldous Huxley; "the medicine is efficacious in stopping a cough"
a question raised for consideration or solution; "our homework consisted of ten problems to solve"
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"
the fundamental assumptions from which something is begun or developed or calculated or explained; "the whole argument rested on a basis of conjecture"
the most important or necessary part of something; "the basis of this drink is orange juice"