Loathe Ted holding group back (6)
I believe the answer is:
detest
'loathe' is the definition.
(I've seen this in another clue)
'ted holding group back' is the wordplay.
'holding' means one lot of letters goes inside another.
'group' becomes 'set' (both can mean a collection).
'back' shows that the letters should be reversed in order.
'ted' enclosing 'set' is 'tseted'.
'tseted' reversed gives 'DETEST'.
(Other definitions for detest that I've seen before include "can't stand" , "Be unable to stand" , "Dislike intensely, loathe" , "Dislike intensely, think badly of" , "Dislike thoroughly" .)