Tousled beauty had fun avoiding Romeo (11)
I believe the answer is:
dishevelled
'tousled' is the definition.
(both can mean untidy or messy)
'beauty had fun avoiding romeo' is the wordplay.
'beauty' becomes 'dish' (slang term for an attractive person).
'had fun' becomes 'revelled'.
'avoiding' indicates named letters should be taken away.
'romeo' becomes 'R' (phonetic alphabet: alpha, bravo, charlie etc.).
'revelled' with 'r' removed is 'evelled'.
'dish'+'evelled'='DISHEVELLED'
(Other definitions for dishevelled that I've seen before include "ill-groomed" , "In mess" , "(Of hair or clothing) untidy" , "(Of hair, clothes) untidy" , "Not well turned out" .)