Northern rich girl occasionally gets nothing (5)
I believe the answer is:
nihil
'nothing' is the definition.
('nihil' means 'nothing' in Latin)
'northern rich girl occasionally' is the wordplay.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'occasionally' indicates alternate letters.
'rich'+'girl'='richgirl'
The alternate letters of 'richgirl' are 'ihil'.
'n'+'ihil'='NIHIL'
'gets' is the link.
(Other definitions for nihil that I've seen before include "love" , "'... obstat' - Catholic imprimatur or approval" , "Nothing (Latin)" .)