problem

noun

1. a state of difficulty that needs to be resolved

   noun.state

   Examples

   She and her husband are having problems.

   Urban problems such as traffic congestion and smog.

   Synonyms job

   Source: WordNet 3.0

2. a question raised for consideration or solution

   noun.communication

   Examples

   Our homework consisted of ten problems to solve.

   Source: WordNet 3.0

3. a source of difficulty

   noun.cognition

   Examples

   What's the problem?

   Synonyms trouble

   Source: WordNet 3.0

4. 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.

   noun

   Source: webster1913