From Longman Dictionary of Contemporary Englishgo in phrasal verbCOVERwhen the sun or the moon goes in, cloud moves in front of it so that it cannot be seen → go→ See Verb table
Examples from the Corpus
go in• It was getting cold, so we went in.• Make sure you wipe your feet before you go into the house.• There was a man at the door trying to stop people from going in.• Don't go in my room - it's a mess. 