Solve the bottom-of-the-harbour problem? (6)
I believe the answer is:
dredge
'solve' is the definition.
Although both the answer and definition are verbs in their base form, I cannot see how they can define each other.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for dredge that I've seen before include "Dig up mud from river or canal bed" , "Search" , "Remove earth from under water" , "Clear (riverbed)" , "Clean out the bed of a river or harbour" .)