Cut out of slope (3)
I believe the answer is:
lop
'cut out' is the definition.
(thesaurus)
'of slope' is the wordplay.
'of' indicates a hidden word.
'LOP' is hidden in the letters of 'slope'.
(Other definitions for lop that I've seen before include "Hack" , "Prune, cut the top off" , "Cut (e.g. branch off)" , "Chop (off)" , "Cut off, tree branches say" .)