Earl managed to get kiss to calm down (5)
I believe the answer is:
relax
'to calm down' is the definition.
(I've seen this in another clue)
'earl managed to get kiss' is the wordplay.
'managed' indicates anagramming the letters.
'to get' says to put letters next to each other.
'kiss' becomes 'x' (X can represent a kiss).
'earl' anagrammed gives 'rela'.
'rela'+'x'='RELAX'
(Other definitions for relax that I've seen before include "Take it easy, don't be so tense" , "Make (rule) less strict" , "Wind down" , "Unbend" , "Become less tense" .)