terrible lizard

In ancient Greek the word dinosaur means ‘terrible lizard’.

The term "dinosaur" was given in 1842 by Sir Richard Owen and derives from Greek word (deinos) "terrible, powerful, wondrous" (sauros) = "lizard". = Terrible, powerful, wondrous lizard.
It was Sir Richard Owen who found some of the first dinosaur fossils. They were teeth. 
They were pretty big too. He studied many types of animals and was pretty sure that these teeth did not belong to any living animal today. He did however think it was similar to a lizards tooth. So he named the dinosaurs. This discovery caused many others to be curious and they to began looking for dinosaurs.

The word dinosaur really does not mean “terrible-lizard.” Actually, it was originally defined to mean “fearfully-great lizard” by Richard Owen in 1842. The Greek word deinos, when used as a superlative, means “fearfully-great,” as used by Homer in The Iliad. It became simplified over time, as an adjective, to mean “terrible.” In reality, scientists believe that dinosaurs are neither “terrible” nor “lizards!”

When the secrets of prehistoric life were unearthed, scientists tried to picture the feelings of those confronted by the great monsters whose fossil bones were coming again to light. Sir Richard Owen (English, 1804-1892) named a few of these creatures, from Greek words. Thus there was the terrible (fearful) lizard (Gk., deinos, “fearful,” plus sauros, “lizard”).