Note enclosing an invoice, primarily for wine (7)
I believe the answer is:
chianti
'wine' is the definition.
(Chianti is an example)
'note enclosing an invoice primarily' is the wordplay.
'note' becomes 'chit' (I've seen this before**).
'enclosing' indicates putting letters inside.
'primarily' suggests taking the first letters.
The first letter of 'invoice' is 'i'.
'chit' going around 'an' is 'chiant'.
'chiant'+'i'='CHIANTI'
'for' acts as a link.
(Other definitions for chianti that I've seen before include "Popular dry red wine of Tuscany" , "European wine" , "Tuscan red wine" , "Italian wine variety" , "Dry red Italian wine" .)