Cringe as old king displays love (6)
I believe the answer is:
grovel
'cringe' is the definition.
(I know that cringe can be written as grovel)
'old king displays love' is the wordplay.
'old king' becomes 'GR' (Georgius Rex, Latin for King George).
'displays' indicates anagramming the letters (I've seen 'displayed' mean this (letters displayed in another way)).
'love' anagrammed gives 'ovel'.
'gr'+'ovel'='GROVEL'
'as' acts as a link.
(Other definitions for grovel that I've seen before include "Crawl, fawn" , "Cringe in abject manner" , "Creep" , "Behave obsequiously, humble oneself" , "Crawl abjectly" .)