n. synonymous with reversion.
• (n.) Reversion. • (n.) One who, or that which, reverts.
(n) Reverter is the event by which a property transferred to another person is returned back to the original owner on due fulfillment of the provisions contained in the original deed of transfer. For example when the loan secured on the property is closed the pledged property reverts to the owner.
Re·vert'er noun 1. One who, or that which, reverts. 2. (Law) Reversion. Burrill. 
See: reversion