get back

verb5

1. •
   Return to where one came from.

   • When I get back from holiday, I expect the house to be tidy.
2. •
   Reply (to someone); follow up (with someone).

   • I'll get back to you on that by Wednesday.
   • Please get back to me about his complaint. ["to" here connotes "reply".]
3. •
   To retrieve (something); to have (something) returned.

   • I lent her my guitar over the Christmas holidays, and will get it back when the term starts.
4. •
   To do something to hurt or harm (someone) who has hurt or harmed one; to take revenge.

   • I'll get you back for this!
   • I'll get him back for this!
5. •
   (US, informal) To repay; to return the favor.