adjective Returned or restored to a previous place or condition.
He was on vacation, but now he’s back.
adjective Not current.
I’d like to find a back issue of that magazine.
adjective Situated away from the main or most frequented areas.
They took a back road.
adjective In arrears; overdue.
They still owe three months’ back rent.
adjective Moving or operating backward.
back action
adjective Pronounced with the highest part of the body of the tongue toward the back of the mouth, near the soft palate (most often describing a vowel).
The vowel of lot has a back vowel in most dialects of England.