1.
If you call someone in, you ask them to come and help you or do something for you.
Call in an architect or surveyor to oversee the work.
PHRASAL VERB: V P n (not pron)
2.
If you ~ somewhere, you make a short visit there.
He just calls in occasionally...
I got into the habit of calling in on Gloria on my way home.
= drop in
PHRASAL VERB: V P, V P on n