Business transaction restricted by one’s principles (6)
I believe the answer is:
ideals
'principles' is the definition.
(I've seen this before)
'business transaction restricted by one's' is the wordplay.
'business transaction' becomes 'deal' (I've seen this in another clue).
'restricted by' indicates putting letters inside (inserted letters are restricted or trapped).
'one's' becomes 'i's' (Roman numeral).
'deal' placed into 'is' is 'IDEALS'.
(Other definitions for ideals that I've seen before include "Standards to aim for" , "High values for ladies" , "Dreams" , "Moral standards" , "Bad ladies have high principles" .)