Screw up (7)
(Other definitions for crumple that I've seen before include "Suddenly lose composure" , "Become crushed" , "Pucker" , "Go to pieces" , "Crush (paper)" .)
'screw up' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for tighten that I've seen before include "Give an extra turn" , "Make harder to undo" , "get tense" , "increase tension" , "becoming tense" .)
'screw up' is the definition.
(I know that screw up can be written as botch)
This is all the clue.
(Other definitions for botch that I've seen before include "Mend clumsily" , "Make a mess of through poor or clumsy work" , "Repair badly" , "Mess up (a task)" , "Carry out (task) badly" .)