Cry about king in fight (5)
I believe the answer is:
brawl
'in fight' is the definition.
(I've seen this before)
'cry about king' is the wordplay.
'cry' becomes 'bawl' (synonyms).
'about' is an insertion indicator.
'king' becomes 'R' (abbreviation for rex, king in Latin).
'bawl' enclosing 'r' is 'BRAWL'.
(Other definitions for brawl that I've seen before include "Abounding" , "Affray" , "Melee" , "Riotous fight" , "Rowdy fight" .)