Trouble from elements in stag groups? (5)
I believe the answer is:
aggro
'trouble' is the definition.
(short for aggression or aggravation)
'elements in stag groups?' is the wordplay.
'elements in' indicates a hidden word (I've seen this in other clues).
'AGGRO' is hidden in the letters of 'stag groups'.
'from' is the link.
(Other definitions for aggro that I've seen before include "Nasty behaviour" , "Big trouble" , "In slang, hassle or troublemaking" , "Trouble; forceful behaviour" , "Greek consumed by past" .)