Definitions of mark-up
the amount by which the price of something is increased before it is re-sold
Tesco's premium on lamb is 26%, while Asda claims its mark-up is only 5%.
when negotiating the terms of an agreement, a version of the draft agreement produced by the lawyers acting for one of the parties showing changes (usually blacklined) to an earlier version produced by the other side
The buyer's solicitors produced a mark-up of the draft contract.