stab in the dark

dark cloud

A situation or future event that causes worry, problems or unhappiness, likened to such a cloud overhead in the sky.

dark horse

Someone who possesses talents or favorable characteristics that are not known or expected by others.

have a stab

To make an attempt, a try.

look on the dark side

To examine a situation, usually unfavorable, from a negative perspective; to be pessimistic or miserable.

oh dark hundred

Some unspecified hour in the early morning (implies an unpleasant time to be awake)

oh dark thirty

Some unspecified hour in the early morning (implying an unpleasant time to be awake).

see the dark side of the moon

To do or experience something exceedingly difficult or rare.

shot in the dark

A guess, attempt, or choice made with little or no evidence or knowledge.