Grind at restructured business (7)

I believe the answer is:

trading

I'm a little stuck... Click here to teach me more about this clue!

'business' is the definition.
(thesaurus)

I don't understand the rest of the clue.

(Other definitions for trading that I've seen before include "Buying and selling" , "Commercial activity" , "in the marketplace" , "Exchanging; a word used in the first ever 2 dn" , "In business" .)

I've seen this clue in The Sun.

Want a hint initially instead of a full solution? Install my app