lookup history

Comprehensive
Dictionary Suite
Help
Help
Help
Look-up History
Your look-up history is saved temporarily in the session. Please log in to saved it in your own account, and subscribe for unlimited saving.
Show words looked up
Find a word or date [Clear]
WordSort by Word # DateSort by Date Definition Site Level
plate tectonics 1 today (used with a singular verb) a theory that scientists use to explain the movement of continents, the eruption of volcanoes, and other changes or events in the earth's geology. The theory of plate tectonics says that the earth's crust is made up of separate sections that are like very large plates. These sections move around constantly because they float on melted rock. The movement of these sections of the crust causes earthquakes. Kids Ch.