Collect crops
I believe the answer is:
'collect crops' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for reap that I've seen before include "Cut the corn" , "Harvest (a crop)" , "'As you sow, so shall you . . . .'" , "''As you sow, so you . . . .'' (4)" , "Use a scythe" .)