A freak is a person who is physically deformed or transformed due to an extraordinary medical condition or body modification. This definition was first attested with this meaning in the 1880s as a shorter form of the phrase "freak of nature", itself a broader term attributed at least as far back as 1847.

What is considered to be a freak?

Freak is a not-so-nice noun that refers to either a person who expresses such an intense obsession with something that it resembles addiction, or a person or animal that is monstrous and deformed. ... Weirdo is slang for freak, and regular is its antonym.

Is it wrong to call someone a freak?

This term is generally agreed to be offensive toward a person or group of people. We strongly recommend you do not use this term and instead use a term not usually thought to be offensive.