ad·join 
(ə-join)
(ə-join)v. ad·joined, ad·join·ing, ad·joins
v.tr.
1. To be next to; be contiguous to: property that adjoins ours.
2. To attach: "I do adjoin a copy of the letter that I have received" (John Fowles).
v.intr.
To be contiguous.
[Middle English ajoinen, from Old French ajoindre, ajoin-, from Latin adiungere, to join to : ad-, ad- + iungere, to join; see yeug- in the Appendix of Indo-European roots.]