Geologist (noun)

1. A person who studies the Earth, including its structure, composition, and processes.
2. A person who specializes in the physical, chemical, and biological processes that shape the Earth's crust.

Origin:

From the greek word 'geologia', meaning 'study of the earth'.

Examples:

1. The geologist was able to identify the mineral deposits in the area.
2. She works as a geologist for a large oil company.
3. He has been a practicing geologist for over 20 years.
4. Geologists use a variety of tools and techniques to study the Earth.
5. A career as a geologist can be both challenging and rewarding.