PO box
PO box · PO boxes
A post office box; a lockable box hired from the postal authorities or a private…A post office box; a lockable box hired from the postal authorities or a private company as a collection point for mail.
Meaning
1 sensesA post office box; a lockable box hired from the postal authorities or a private company as a collection point for mail.
a numbered compartment in a post office where mail is put to be called for