Innocent king follows ethnic diversity (2,3,5)
I believe the answer is:
in the clear
'innocent' is the definition.
(similar in meaning)
'king follows ethnic diversity' is the wordplay.
'king' becomes 'lear' (King Lear).
'follows' says to put letters next to each other.
'diversity' indicates an anagram (a diverse or different spelling).
'ethnic' is an anagram of 'inthec'.
'lear' after 'inthec' is 'IN THE CLEAR'.
(Other definitions for in the clear that I've seen before include "got off Scot-free!" , "out of a difficulty" , "No longer under suspicion" , "Free of suspicion, guilt or blame" , "out of the wood" .)