Geothermal energy – Energy generated by heat stored deep in the earth

In order to learn the term geothermal we need to break down the word and remember it's parts:

Geo = earth

Thermal = heat

The way to remember thermal is heat:

My Thermos flask always has a hot drink in it.

Thermal = heat

The way to remember that Geo is earth:

Gee! we owe (geo) everything to the earth.

Geo = earth

So

Geothermal = Earth Heat
or heat from the earth

Geothermal is heat from the earth that can be used to heat things like a house:

Pipes buried in the earth with water circulating through them can be used to heat a house.