Abbey on drumlin has hidden past (6)
I believe the answer is:
beyond
'past' is the definition.
(I've seen this before)
'abbey on drumlin has hidden' is the wordplay.
'hidden' indicates a hidden word.
'BEYOND' is hidden in the letters of 'abbey on drumlin has'.
(Other definitions for beyond that I've seen before include "On the far side of" , "Further than or outside the scope of" , "Outside the range of" , "Farther along in space, time or degree" , "Better than" .)