(idiomatic) sequential or consecutive, in the case of exactly three events.

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

Alternative form of back to back

A house with a party wall at the rear.

Alternative form of back-to-back

With one's back facing that of somebody else. / Consecutively; one after the other. / (poker slang) Synonym of wired (“being a pair in seven card stud with one face up and one face down”)

plural of back-to-back

At or near the rear. / (predicative) Returned or restored to a previous place or condition. / Not current. / Situated away from the main or most frequented areas. / In arrears; overdue.

(not comparable) To or in a previous condition or place. / In a direction opposite to that in which someone or something is facing or normally pointing.

Before now; ago.