Scientist (noun)

1. A person who is engaged in scientific research or study.
2. An expert in a particular field of science.

Origin:

Mid 19th century: from science, on the pattern of artist.

Examples:

1. He is a scientist at the research lab.
2. She is a scientist in the field of biology.
3. The scientists studied the effects of pollution on the ocean.
4. The scientist made an important discovery.
5. The scientist presented the findings at the conference.