King gets the French to take it easy (5)
I believe the answer is:
relax
'take it easy' is the definition.
(I've seen this in another clue)
'king gets the french' is the wordplay.
'king' becomes 'rex' ('king' in Latin).
'gets' indicates putting letters inside (gets can mean captures or absorbs).
'the french' becomes 'la' ('the' in French).
'rex' going around 'la' is 'RELAX'.
'to' acts as a link.
(Other definitions for relax that I've seen before include "Chill out" , "Unbend" , "Put your feet up" , "Abate" , "Hang loose" .)