Law? Did I say, by law or by definition or neither?
Television (TV) is a telecommunication medium used for transmitting moving images in monochrome (black and white), or in colour, and in two or three dimensions and sound. The term can refer to a television set, a television program ("TV show"), or the medium of television transmission. Television is a mass medium for entertainment, sports, education, news, courtroom drama, vintage programming, politics, gossip and advertising.
None of these apply to a device without a tuner capable of receiving a television broadcast.
No matter, you can't change my mind. A TV without a tuner is a monitor.