Get to know king and knight (5)
I believe the answer is:
learn
'get to know' is the definition.
('learn' can be a synonym of 'get to know')
'king and knight' is the wordplay.
'king' becomes 'lear' (I've seen this before).
'and' is a charade indicator (letters next to each other).
'knight' becomes 'n' (chess).
'lear'+'n'='LEARN'
(Other definitions for learn that I've seen before include "Study or digest" , "Gain knowledge or skills" , "Take in" , "Con" , "Acquire information" .)