Fossil word is a term used in linguistics to describe a word that is no longer in everyday use but is still preserved in certain expressions or phrases.

Scientists discovered several body fossils during the excavation.

The fossil waters found in the underground reservoirs are millions of years old.

The fossil found in the damascus was millions of years old.

Renewable energy sources such as wind and solar power are considered non-fossil alternatives.

The fossil twister was discovered in the ancient ruins.

I drove my fossil car to work today.