push-to-talk - Computer Definition
A feature of walkie-talkies and certain cellphones and instant messaging services that provides instant voice connectivity to the party on the other end. Push-to-talk is a one-way (half-duplex) communication. When you want to talk, you press and hold down a button on the phone, or hold down the mouse button or space bar on the computer. Letting go of the button gives the other person an opportunity to push-to-talk. Nextel popularized the push-to-talk feature on its cellphone service.