scheme; plan; policy; step; means

plan, policy

question, problem on homework etc. / a question; a matter (of time etc.) / a problem (something that needs to be dealt with); a trouble / an issue; a matter

as far as ... is concerned; in terms of ...

a target, a mark, a bullseye / an objective, an object (of doing something)

(computing) name resolution

unsolved, unresolved

(attributively) unsolved

necessary evil

necessity (quality or state of being necessary, unavoidable, or absolutely requisite)