Definition & Meaning of "kook"in English

What is the origin of the term "kook" and how is it used?

"Kook" is an English slang term that appeared in the early 20th century, likely derived from "cuckoo," referencing the bird and the slang association with craziness. It describes someone who is eccentric, crazy, or bizarre, often emphasizing unusual behavior rather than outright danger. The term is used in informal speech, sometimes playfully or teasingly, especially in subcultures like surfing or skateboarding. It is mildly derogatory, highlighting oddness or unconventional behavior, but is generally not deeply offensive.