walk in

verb

1. To come without an appointment to a place that would normally require one.

   “If you walk in, you're going to have to wait at least an hour.”

   “You can't just walk in, Mam. You have to make an appointment.'”

2. To step to the rack again with after having stepped away in order not to hit it during execution of the exercise.
3. Used other than figuratively or idiomatically: see walk, in.

   “There, characteristically, he refused to be carried on a stretcher, saying he was too heavy for nurses. He walked in with their support.”