call in phrasal verb ( see also ↑ call )
1 . call somebody/something ↔ in to ask someone to come and help you with a difficult situation:
The government then called in troops to deal with the disturbances.
2 . to telephone somewhere, especially the place where you work, to tell them where you are, what you are doing etc:
Rachael called in sick (=telephoned to say she was too ill to come to work) .
3 . to telephone a radio or television show to give your opinion or to ask a question:
Over 2,000 viewers called in with complaints about the bad language used in the programme.
4 . call in a loan/debt to officially tell someone to pay back money you lent them:
The bank can call in the loan at any time.
5 . British English to visit a person or place while you are on your way to somewhere else
call in on/at
Could you call in on Mum on your way home?