a thing that is difficult to deal with or to understand. big/serious/major problems; She has a lot of health problems. financial/social/technical problems ...

a thing that is difficult to deal with or to understand; big/major/serious problems; health/family, etc. problems; financial/practical/technical problems.

problem adjective NAmE//ˈprɑbləm// [only before noun] causing problems for other people She was a problem child, always in trouble.

There are nine meanings listed in OED's entry for the noun problem, three of which are labelled obsolete. See 'Meaning & use' for definitions, usage, ...

adjective. /ˈprɒbləm/ /ˈprɑːbləm/ [only before noun] ​causing problems for other people or yourself.

noun /ˈprɒbləm sɒlvɪŋ/ /ˈprɑːbləm sɑːlvɪŋ/ [uncountable] the act of finding ways of dealing with problems.

noun [uncountable] the act of finding ways of dealing with problems to develop problem-solving skills and strategies.

something that causes difficulty or that is hard to deal with: Financing the camp's athletic program is a problem.

trouble · ​. [uncountable, countable] a problem, worry, difficulty, etc. or a situation causing this · ​. [uncountable] a situation in which you can be criticized ...

What does the verb problem-solve mean? There is one meaning in OED's entry for the verb problem-solve. See 'Meaning & use' for definition, usage, and quotation ...