Elevated area is area in large land mass (4)
I believe the answer is:
asia
'large land mass' is the definition.
'elevated area is area in' is the wordplay.
'elevated' is a reversal indicator.
'in' indicates the answer is hidden within the clue.
'aisa' is hidden within 'area is area'.
'aisa' back-to-front is 'ASIA'.
(Other definitions for asia that I've seen before include "It has most of the earth's population" , "The nations of the East, collectively" , "populous region" , "Populous continent" , "A vast number of people have lived here" .)