Do a crossword, say
I believe the answer is:
solve
'do a crossword say' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for solve that I've seen before include "Work out (a clue)" , "Clear up a mystery" , "Get answer to (a clue)" , "Unravel (a problem)" , "Explain (a mystery)" .)