Great elk has dined (3)
I believe the answer is:
ate
'dined' is the definition.
(I've seen this in another clue)
'great elk has' is the wordplay.
'has' indicates the answer is hidden within the clue.
'ATE' can be found hidden inside 'great elk'.
(Other definitions for ate that I've seen before include "upset > Greek goddess" , "Worried" , "mischief-maker" , "Had at meal" , "included in one's diet" .)