Gradually landowning class swaps sides (6)
I believe the answer is:
gently
'gradually' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for gently that I've seen before include "in a peaceful manner?" , "Mildly, kindly" , "In mild and moderate manner, not in rough way" , "Lightly, mildly, softly" , "Mildly; gradually" .)