contiguous

Connected; touching; abutting.

Adjacent; neighboring.

1730–1774, Oliver Goldsmith, Introductory to Switzerland Though poor the peasant’s hut, his feasts though small, He sees his little lot the lot of all; Sees no contiguous palace rear its head To shame the meanness of his humble shed;

[…] the usual quietness of the day, with us, was broken in upon by the shout of success from the pursuing boats, followed by vehement respondings from the contiguous ship.

Connecting without a break.

the forty-eight contiguous states

Supposing three such houses to be contiguous to a central one, each separated from the latter by a straight wall.