List of charges sailor provided fisherman initially (6)
I believe the answer is:
tariff
'list of charges' is the definition.
(list of fees or charges to be paid)
'sailor provided fisherman initially' is the wordplay.
'sailor' becomes 'tar' (slang term for a sailor).
'provided' becomes 'if' (eg 'provided it's sunny' means 'if it's sunny').
'initially' indicates taking the first letters.
The initial letter of 'fisherman' is 'f'.
'tar'+'if'+'f'='TARIFF'
(Other definitions for tariff that I've seen before include "List of prices displayed as in pub" , "List of customs duties" , "Government tax on imports" , "Price list - import tax" , "Import/export tax" .)