Swinger with nude model getting stuck into fruit (8)
I believe the answer is:
pendulum
'swinger' is the definition.
(something which swings)
'nude model getting stuck into fruit' is the wordplay.
'model' indicates anagramming the letters.
'getting stuck into' is an insertion indicator.
'fruit' becomes 'plum' (plum is a kind of fruit).
'nude' anagrammed gives 'endu'.
'endu' going inside 'plum' is 'PENDULUM'.
'with' acts as a link.
(Other definitions for pendulum that I've seen before include "Swinger in clock" , "A swinging weight as in old clock" , "Oscillating mechanism" , "Vacillator" , "Swinging part of clock" .)