Cut groin badly on end of tightrope (6)
I believe the answer is:
ignore
'cut' is the definition.
('ignore' can be a synonym of 'cut')
'groin badly on end of tightrope' is the wordplay.
'badly' is an anagram indicator.
'on' says to put letters next to each other.
'end of' suggests the final letters.
The last letter of 'tightrope' is 'e'.
'groin' with letters rearranged gives 'ignor'.
'ignor'+'e'='IGNORE'
(Other definitions for ignore that I've seen before include "Spurn" , "Slight" , "Forget" , "Deliberately take no notice" , "Dismiss" .)