Current business, weak (6)
I believe the answer is:
infirm
'weak' is the definition.
('infirm' can be a synonym of 'weak')
'current business' is the wordplay.
'current' becomes 'in' (I've seen this in other clues).
'business' becomes 'firm' (firm is a kind of business**).
'in'+'firm'='INFIRM'
(Other definitions for infirm that I've seen before include "Feeble, decrepit" , "Doddery" , "Not in good health" , "Not physically strong" , "Frail" .)