Dangly bit of gold captivating sweetheart on return (5)
I believe the answer is:
uvula
'dangly bit' is the definition.
(dangly piece of flesh in the throat)
'gold captivating sweetheart on return' is the wordplay.
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'captivating' indicates putting letters inside (I've seen this in other clues).
'sweetheart' becomes 'luv' (both are terms of endearment).
'on return' is a reversal indicator.
'au' going around 'luv' is 'aluvu'.
'aluvu' back-to-front is 'UVULA'.
'of' is the link.
(Other definitions for uvula that I've seen before include "Fleshy projection hanging from roof of mouth" , "Part of one's mouth" , "Fleshy lobe" , "Fleshy body over back of tongue" , "Flap at the back of the soft palate" .)