Funny A-lister entertains King's Head, twinkling? (8)
I believe the answer is:
starlike
'twinkling?' is the definition.
'funny a-lister entertains king's head' is the wordplay.
'funny' is an anagram indicator.
'entertains' indicates putting letters inside.
'head' says to take the initial letters.
The first letter of 'kings' is 'k'.
'a'+'lister'='alister'
'alister' anagrammed gives 'starlie'.
'starlie' going around 'k' is 'STARLIKE'.
(Other definitions for starlike that I've seen before include "Resembling pointed object" , "bright, perhaps?" , "celestial body might be?" , "bright but quite small?" .)