Definition & Meaning of "sicko"in English

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

"Sicko" is an English slang term that appeared in the mid-20th century, formed from "sick" with the informal suffix "-o." It draws on the metaphor of illness to describe someone seen as morally perverted, psychologically disturbed, or mentally unbalanced, suggesting their behavior is abnormal or disturbing. The term is used in informal speech, media, and online contexts, often in condemnation or disgust, especially regarding shocking or taboo behavior. It is clearly derogatory, targeting a person's character or mental state, and is not neutral or reclaimed.