adjective
Sequential or consecutive.
With one's back facing that of somebody else.
(physics, by extension) Emerging in exactly opposite directions.
(of a house) Having a party wall at the rear.
(poker slang) Synonym of wired (“being a pair in seven card stud with one face up and one face down”).
adverb
Alternative form of back to back.
noun
A house with a party wall at the rear.
(oil industry) One of a pair of rig workers who are rostered on alternately.