Frat (noun)

1. A social club or organization for students, particularly in a college or university, usually consisting of men and having a particular name or symbol.
2. A group of friends who share a common interest or activity, especially among college students.

Origin:

Shortened form of fraternity, the word frat originates from the late 19th century, it's used as an informal and colloquial term to refer to a social club or organization.

Examples:

1. He was a member of a frat in college.
2. The frat boy lifestyle is often associated with partying and drinking.
3. The frat house was the center of social activity on campus.
4. The frat members were known for their rowdy behavior.
5. He joined the frat to make friends and have a good time.