Moving easily and elegantly (8)
I believe the answer is:
graceful
'moving easily and elegantly' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for graceful that I've seen before include "Moving easily and elegantly" , "Elegant in movement or manner" , "Elegant and moving easily" , "Showing elegance of manner or movement" , "Fluid" .)