The American Heritage® Dictionary of the English Language, 4th Edition
n. An information service in which data is transmitted over television cables or telephone lines and displayed on a television or computer screen in the home.
n. Any of various early information retrieval services, such as viewdata and Teletext systems, that delivered pages of computerized text to users on request.
Word Usage
"The generic system name viewdata became obsolete due to depositing the brand name and was dubbed videotex – the Latin word combination for I see text."