Celebrity, good person meeting a king (4)
I believe the answer is:
star
'celebrity' is the definition.
(a star is a celebrity or famous person)
'good person meeting a king' is the wordplay.
'good person' becomes 'st' (saint).
'meeting' means one lot of letters go next to another.
'king' becomes 'R' (abbreviation of Latin rex).
'st'+'a'+'r'='STAR'
(Other definitions for star that I've seen before include "Heavenly light" , "Leading actor in a show" , "Public figure" , "eg The sun" , "Five-pointed celestial body" .)