Irritation born out of spite (9)
I believe the answer is:
itchiness
'irritation' is the definition.
(irritation somewhere on the body)
'born out of spite' is the wordplay.
'born' becomes 'b'.
'out of' indicates named letters should be taken away.
'spite' becomes 'bitchiness' (spiteful behaviour).
'bitchiness' with 'b' removed is 'ITCHINESS'.
(Other definitions for itchiness that I've seen before include "Feeling of irritation" , "irritating" , "It produces the desire to scratch" , "some experience after seven years in union?" , "tingling" .)