Tackle, as a crossword (5)
I believe the answer is:
solve
'tackle as a crossword' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for solve that I've seen before include "Unscramble" , "Find the 3dn to a mystery" , "Work out (a clue)" , "Get answer to (a clue)" , "Figure out the answer" .)