Definition of "dial-up"

dial-up

adjective
not comparable
1. (computing, of a connection to a network) Requiring a telephone number to be dialed.
  Quotations
  In dial-up networking, both your PC and the remote system run network-protocol (called TCP/IP) software. When your PC dials up and sets up a communication path, the network protocols exchange data packets over that dial-up connection.
  2004, Naba Barkakati, “Setting Up Dial-Up Networking”, in Red Hat Fedora Linux 2 All-in-One Desk Reference For Dummies, John Wiley & Sons, page 285
noun
plural dial-ups
1. (computing) A network connection that requires a telephone number to be dialed.