One who, or that which, abuts, specifically, the owner of a contiguous estate.
the abutters on a street or a river
2015 April 23, James Kinsella writing in The Enterprise, Heritage Hearing Boils Over
Residents continually brought up the aerial park, which had been quickly approved by the committee a year earlier after Heritage failed to notify abutters about the proposal. And Mr. Collins continually banged his gavel to cut them off.