Entertaining king and queen, celebs revealing all (8)
I believe the answer is:
starkers
'revealing all' is the definition.
(informal term for naked)
'entertaining king and queen celebs' is the wordplay.
'entertaining' is an insertion indicator.
'king' becomes 'k'.
'and' means one lot of letters go next to another.
'queen' becomes 'er' (abbreviation for Elizabeth Regina).
'celebs' becomes 'stars'.
'k'+'er'='ker'
'ker' placed inside 'stars' is 'STARKERS'.
(Other definitions for starkers that I've seen before include "Like fairytale emperor" , "23 [NUDIST]" , "Bare (colloq.)" , "in the buff" , "Slangily naked" .)