Trick by one stealing gold crown (6)
I believe the answer is:
corona
'crown' is the definition.
(I've seen this before)
'trick by one stealing gold' is the wordplay.
'trick' becomes 'con' (I've seen this before).
'by' is a charade indicator (letters next to each other).
'one' becomes 'a'.
'stealing' is an insertion indicator.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'con'+'a'='cona'
'cona' placed around 'or' is 'CORONA'.
(Other definitions for corona that I've seen before include "A glow of light around something" , "It's visible as a halo during a solar eclipse" , "Big Smoke" , "Glow around the sun" , "Gaseous envelope of sun" .)