Definition of "go in"

go in

verb
third-person singular simple present goes in, present participle going in, simple past went in, past participle gone in
1. Used other than figuratively or idiomatically: see go,‎ in.
2. To become obscured by clouds. (of the sun, moon or stars)
3. To share in part of a project's or plan's duties or costs.
4. (of a fact or concept) To become understood or accepted.
5. To perform invasive surgery.
  Quotations
  Our next step is to meet with Dr. Wells (surgeon) to discuss our next step. It looks like he will have to go in and see exactly what it is, then if cancer, extract it.
  2012, Tim Layman, Death Was Not an Option!, page 73