verb (v)

• lie adjacent to another or share a boundary(verb.contact)

  Example:
  Canada adjoins the U.S..
  

  Synonym:
  abut, border, butt, butt against, butt on, edge, march
  

  source: wordnet30
• be in direct physical contact with; make contact(verb.contact)

  Synonym:
  contact, meet, touch
  

  source: wordnet30
• attach or add(verb.change)

  Example:
  I adjoin a copy of your my lawyer's letter.
  

  source: wordnet30
• To join or unite to; to lie contiguous to; to be in contact with; to attach; to append.(verb)

  source: webster1913
• To lie or be next, or in contact; to be contiguous; as, the houses adjoin.(verb)

  source: webster1913