The phrase "cold shoulder" refers to a social behavior where someone intentionally ignores or shows indifference to another person. This can manifest through body language, such as turning away or avoiding eye contact, and is often used as a way to express disapproval or rejection without direct confrontation. The origin of the term is believed to come from the practice of serving a cold shoulder of meat to guests who were no longer welcome. This gesture symbolized that the host was no longer interested in entertaining the guest, reinforcing the idea of social exclusion.