Repulsive women try to cuddle up, hugging Romeo (7)
I believe the answer is:
gorgons
'repulsive women' is the definition.
'try to cuddle up hugging romeo' is the wordplay.
'try' becomes 'go' (go is a kind of try**).
'to cuddle' becomes 'snog'.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'hugging' indicates putting letters inside.
'romeo' becomes 'r' (phonetic alphabet: alpha, bravo, charlie etc.).
'snog' back-to-front is 'gons'.
'go'+'gons'='gogons'
'gogons' placed around 'r' is 'GORGONS'.
(Other definitions for gorgons that I've seen before include "fierce women" , "Mythical Greek sisters whose look turned people to stone" , "Monstrous sisters" , "Ugly sisters" , "Three winged sister monsters with 'hair' of writhing snakes" .)