See Mordor easily on the way back circling airfield (9)
I believe the answer is:
aerodrome
'airfield' is the definition.
(aerodrome is a kind of airfield)
'see mordor easily on the way back circling' is the wordplay.
'circling' indicates the answer is hidden within the clue (the answer is circled or surrounded by the clue).
'on the way back' says the letters should be written in reverse.
'emordorea' is hidden in the letters of 'see mordor easily'.
'emordorea' in reverse letter order is 'AERODROME'.
(Other definitions for aerodrome that I've seen before include "Point of arrival, perhaps" , "landing zone" , "Where one might land" , "landing area" , "Small airport" .)