- An attachment or supplement added to a finished written document, such as a contract, often to propose changes, clarify details, or explain something. It is especially common in real estate sales where details like payment methods, included appliances, title transfer date, and seller financing terms are hammered out after the initial contract
- The buyer proposed an addendum to the contract outlining the schedule of payments.
- Although the sale was agreed upon, the seller included an addendum specifying which appliances would stay with the house.
- To avoid any confusion about the contract terms, they attached a signed addendum detailing the financing plan.