1) Abutting 2) Adjacent 3) Adjacent to 4) Against 5) Bordering 6) Connected 7) Conterminous 8) Contiguous 9) Located next to another 10) Neighboring 11) Neighbouring 12) Next to 
• (p. pr. & vb. n.) of Adjoin • (a.) Joining to; contiguous; adjacent; as, an adjoining room.
Ad·join'ing adjective Joining to; contiguous; adjacent; as, an adjoining room. 'The adjoining fane.' Dryden. « Upon the hills adjoining to the city. Shak. » Syn. -- Adjacent; contiguous; near; neighboring; abutting; bordering. See Adjacent
being in contact at some point or line; located next to another; bordering; contiguous: the adjoining room; a row of adjoining town houses.