Teresa grabbing Romeo's hair (5)
I believe the answer is:
tress
'hair' is the definition.
(tress is a kind of hair)
'teresa grabbing romeo's' is the wordplay.
'teresa' becomes 'tess' (I am not sure about this - if you are sure you should believe this answer much more).
'grabbing' means one lot of letters goes inside another.
'romeo' becomes 'R' (phonetic alphabet: alpha, bravo, charlie etc.).
'tess' enclosing 'r' is 'TRESS'.
Can you help me to learn more?
(Other definitions for tress that I've seen before include "Braid of hair" , "Long piece of hair" , "is a bit of a shock" , "Rests (anag.)" , "Obsolete support" .)