Leo gets out a gun with a smooth movement (6)
I believe the answer is:
legato
'smooth movement' is the definition.
'legato' can be an answer for 'smooth' (musical term). I'm not sure about the 'movement' bit.
'leo gets out a gun with a' is the wordplay.
'gets' is an insertion indicator (gets can mean captures or absorbs).
'out a gun' becomes 'gt' (I can't explain this - if you can you should believe this answer much more).
'with' means one lot of letters goes inside another.
'gt' enclosing 'a' is 'gat'.
'leo' enclosing 'gat' is 'LEGATO'.
Can you help me to learn more?
(Other definitions for legato that I've seen before include "with smooth execution" , "Got ale (anag.)" , "In a smooth and flowing manner (music)" , "Smooth, flowing (mus.)" , "Smoothly, musically speaking" .)