King, coming in to occupy throne, twirled this, being playful (8)
I believe the answer is:
skittish
'playful' is the definition.
(I've seen this before)
'king coming in to occupy throne twirled this' is the wordplay.
'king' becomes 'K' (chess abbreviation).
'coming in to' means one lot of letters goes inside another.
'occupy throne' becomes 'sit' (sit on a throne).
'twirled' indicates anagramming the letters (I've seen 'twirling' mean this).
'this' anagrammed gives 'tish'.
'sit'+'tish'='sittish'
'k' going within 'sittish' is 'SKITTISH'.
'being' acts as a link.
(Other definitions for skittish that I've seen before include "Playful, hard to control" , "Frisky or mettlesome" , "Playful in coy manner, frisky" , "(Of horses) excessively lively" , "Frisky or playful (8)." .)