- (transitive) To be in contact or connection with.
- The living room and dining room adjoin each other.
- 2013, Graeme Simsion, The Rosie Project, →ISBN, page 55:
- We were in the living area, which adjoins the kitchen.
- (transitive, mathematics, chiefly algebra and number theory) To extend an algebraic object (e.g. a field, a ring, etc.) by adding to it (an element not belonging to it) and all finite power series of (the element).
- can be obtained from by adjoining to .
to be in contact or connection with