Row involving a restaurant’s first bill of fare (6)
I believe the answer is:
tariff
'bill of fare' is the definition.
(I've seen this before)
'row involving a restaurant's first' is the wordplay.
'row' becomes 'tiff' (tiff is a kind of row).
'involving' means one lot of letters goes inside another.
'restaurant's first' becomes 'r' (tst letter of 'restaurant').
'a'+'r'='ar'
'tiff' placed around 'ar' is 'TARIFF'.
(Other definitions for tariff that I've seen before include "Import or export duty" , "List of fixed charges as in hotel" , "Price list - import tax" , "Government tax on imports" , "Table of fixed charges" .)