on the telephone

on the telephone

Currently using a telephone to talk to another person. Please be quiet! Can't you see I'm on the telephone? I was on the telephone for nearly three hours trying to get through to a customer service representative.
See also: on, telephone
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

*on the telephone

 and *on the phone
Fig. speaking on the telephone. (*Typically: be ~; get ~.) She's on the phone but won't be long. Please take a seat while I'm on the phone. Get on the phone and call him back immediately!
See also: on, telephone
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
See also:
References in classic literature ?
"Someone wishes to speak to your ladyship on the telephone," the girl announced.
"On the telephone, at this time of night?" Lady Ruth exclaimed.
She was amazed to find herself already committed by William and Cassandra to marry the owner of the halting voice she had just heard on the telephone. The tendency of her spirit seemed to be in an altogether different direction; and of a different nature.