Move smoothly and effortlessly (5)
I believe the answer is:
glide
'move smoothly and effortlessly' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for glide that I've seen before include "Move smoothly, as a sailplane" , "Make an unpowered flight" , "Move smoothly and effortlessly" , "Move smoothly and easily" , "Gelid (anag.)" .)