Puking is a slang term that means to vomit. It is an informal word that is often used in casual conversation. When someone is puking, they are experiencing a physical reaction in which the contents of their stomach are expelled through their mouth. This can be caused by a variety of factors, such as illness, food poisoning, or excessive alcohol consumption. The word "puke" is often used interchangeably with other synonyms for vomiting, such as "throwing up" or "barfing".