Kylie dancing after initially lying prone (6)
I believe the answer is:
'prone' is the definition.
'kylie dancing after initially lying' is the wordplay.
'dancing' is an anagram indicator.
'after' says to put letters next to each other.
'initially' suggests taking the first letters.
The first letter of 'lying' is 'l'.
'kylie' is an anagram of 'ikely'.
'ikely' put after 'l' is 'LIKELY'.
(Other definitions for likely that I've seen before include "Quite possible" , "Ilkley (anag.)" , "Probable, expected" , "Has a good chance of being the case" , "In prospect" .)