Wait in
Definition 1 of 1
Pro Tip 1/3Expectant Waiting
Use 'wait in' when you're actively expecting the arrival of someone or something soon. 
I can't join the party, I have to wait in for the technician.
Pro Tip 2/3At Home
'Wait in' usually means staying inside your home, not elsewhere, for something anticipated. 
On Saturday, I need to wait in for a parcel delivery.
Pro Tip 3/3Not Immediate
'Wait in' implies that the person or thing you're waiting for might not come immediately. 
She's waiting in for a call from the doctor's office.