Common words:
* Telegraph: A system for transmitting messages over long distances using electrical signals.
* Telephone: A device for transmitting sound over long distances using electrical signals.
* Television: A system for transmitting images and sound over long distances using electrical signals.
* Telepathy: Communication between minds without using the senses.
* Telekinesis: The supposed ability to move objects by mental effort alone.
* Telescope: An optical instrument for viewing distant objects.
* Telemetry: The transmission of data over long distances using electronic equipment.
Less common words:
* Telecast: A broadcast of a television program.
* Teleconference: A conference in which participants are at different locations and communicate by electronic means.
* Telemedicine: The practice of medicine at a distance using electronic means.
* Telecommuting: Working from home or a remote location using electronic means.
* Telepresence: The ability to experience a remote environment as if you were physically present.
* Teleportation: The hypothetical ability to transport oneself or an object instantly from one location to another.
This is not an exhaustive list, but it should give you a good starting point.