Find the definition of these words.

I.A.L.T upload one of my reading tasks from this week.

For this task I was given three words to find the definition of and the put it into a sentence. The words I had were ancestors, geothermal and vapour. Ancestors are old family. Geothermal is things that are produced by the earths internal heat. Vapour is a liquid that is turned into a gas. What word do you like the most?