get back

1.  Also get back to. Return to a person, place, or condition. For example, What time will you get back? or I hope he'll get back to the subject of this report. [c. 1600]
2.  Recover something, as in When will I get this book back? [c. 1800]

Definition: regain
Antonyms: lose, miss, pass

v

Definition: return
Antonyms: depart, go away, leave

The verb has 4 meanings:

Meaning #1: come back to place where one has been before, or return to a previous activity
  Synonyms: return, go back, come back

Meaning #2: recover something or somebody that appeared to be lost
  Synonym: win back

Meaning #3: take revenge or even out a score
  Synonym: get even

Meaning #4: get one's revenge for a wrong or an injury
  Synonym: settle