a situation or question that is difficult to understand or resolve
something or somebody that causes trouble or harm and is difficult to deal with
somebody who is difficult to deal with or understand
(used before a noun) difficult to deal with; presenting a problem
a problem child
a question raised for enquiry, consideration, or solution
a proposition in mathematics or physics for which a solution has to be found or from which a principle, etc can be demonstrated
(used before a noun) dealing with a moral, social, or human problem
a problem play
[Middle English probleme via French and Latin from Greek problēma, literally ‘something thrown forwards’, from proballein to throw forward, from pro-1 + ballein to throw]