Geek (noun)

1. A person who is socially awkward or not fashionable and is interested in technical or scientific pursuits, especially computing and new technology.
2. A person who is highly knowledgeable and enthusiastic about a specific subject or activity.

Origin:

From the english word "geek" which originally meant a carnival performer who performed grotesque or bizarre acts, such as biting the heads off live chickens. it later came to mean an expert in a particular field of technology or science, or someone with an obsessive interest in a particular hobby or activity.

Examples:

1. He was a computer geek and spent all his free time coding.
2. She was a science geek and loved reading about new discoveries.
3. The group of friends were all geeks and enjoyed playing board games.
4. He was a history geek and knew everything about the Civil War.
5. The comic book store was full of geeks looking for the latest issue.