Whether you call your grandfather clock a Floor Clock, or refer to grandfather clocks as long case clocks or tall case clocks has a lot to do with which side of the Atlantic you were raised, or possibly what century in time one happened to be born into. In the USA and Canada, grandfather clocks have been known as well, grandfather clocks, for well over a hundred years, after the well known Grandfather Clocks Song, which not only swept the nation, but also the North American vernacular.
Historically, in England and Western Europe in general, grandfather clocks were and still are referred to more frequently as Tallcase clocks or Longcase clocks. The Floor Clock vocabulary has been used on both sides of the Atlantic, and has been reinforced over the years by the major makers of grandfather clocks, including Hermle Clocks, the Howard Miller Grandfather Clock company, Ridgeway Floor Clocks, the Bulova Grandfather Clocks Collection, and Kieninger Floor Clocks.
The grandfather clock and floor clock words are used relatively interchangeably today, even by many grandfather clock shoppers today at 1-800-4CLOCKS.
Grandmother Clocks is another term which is frequently asked about, with the only major difference being the height of the clock. Other than the height, in most instances, the two terms can be used reasonably interchangably.
Oh, and grandfather clocks are sometimes referred to as granfather clocks or grandfathers clocks, or even grand father clocks. These are just simple common misconceptions of what the correct words and terminology are.
Granddaughter Clocks are smaller, and Grandson Clocks™, actually introduced by 1-800-4CLOCKS much earlier this year, are even smaller. Keep an eye out for them at a retailer near you.