Cut in the sack covering makeshift grid (8)
I believe the answer is:
abridged
'cut' is the definition.
(similar in meaning)
'in the sack covering makeshift grid' is the wordplay.
'in the sack' becomes 'abed' (lying abed).
'covering' indicates putting letters inside.
'makeshift' indicates anagramming the letters.
'grid' with letters rearranged gives 'ridg'.
'abed' placed around 'ridg' is 'ABRIDGED'.
(Other definitions for abridged that I've seen before include "Abbreviated, contracted" , "Epitomised" , "Shorter" , "Shortened as book may be" , "Cut short - big adder (anag)" .)