Size and Weight:
From its name, you might think Torosaurus was named after a bull ("toro" in Spanish), but the truth is a bit less exciting. The "toro" in this case means "perforated" or "pierced," referring to the large holes in this herbivore's skull, beneath its enormous frill. On the other hand, since the paleontologist who discovered Torosaurus (Othniel C. Marsh) never explained the reasoning behind the name, it's possible that the "pierced" part refers to any predators that ventured too close to Torosaurus' pointy horns!
Names aside, Torosaurus was a typical ceratopsian--the family of horned, frilled, elephant-sized dinosaurs that populated the North American continent during the late Cretaceous period, the most famous examples of which were Triceratops and Centrosaurus. (Update: according to a recent study, Torosaurus may well have been the same dinosaur as Triceratops, since the frills of ceratopsian individuals continued to grow as they aged. Despite what you've read, though, this doesn't meant that we'll have to start referring to Triceratops by this more obscure name!)