Business money secures gripping tool, mostly for machine on plantation (6,3)
I believe the answer is:
cotton gin
'machine on plantation' is the definition.
(machine on a cotton plantation)
'business money secures gripping tool mostly' is the wordplay.
'business' becomes 'co' (short for company).
'money' becomes 'tin' (I've seen this before).
'secures' indicates putting letters inside.
'gripping tool' becomes 'tongs' (tool for gripping things).
'mostly' means to remove the last letter.
'tongs' with its final letter removed is 'tong'.
'tin' going around 'tong' is 'ttongin'.
'co'+'ttongin'='COTTON-GIN'
'for' acts as a link.
(Other definitions for cotton gin that I've seen before include "Machinery in the textiles industry" , "Textile worker" .)