King is encountered — that's destiny (6)
I believe the answer is:
kismet
'that's destiny' is the definition.
(kismet is a kind of destiny)
'king is encountered' is the wordplay.
'king' becomes 'K' (chess abbreviation).
'encountered' becomes 'met' ('meet' can be a synonym of 'encounter').
'k'+'is'+'met'='KISMET'
(Other definitions for kismet that I've seen before include "Will of Allah" , "Fate - 1953 musical" , "Turkish fate, destiny" , "lot in life" , "fortune" .)