Definition & Meaning of "up yours"in English

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

Up yours is a slang expression that appeared in mid-20th-century English to show anger, defiance, or rejection of authority, criticism, or demands. The phrase comes from the literal idea of shoving something "up" someone's anus, used metaphorically to tell them off or dismiss them aggressively. Historically, it was derogatory and insulting, often used in confrontational, rebellious, or disrespectful speech. Today it remains vulgar and offensive, generally used in informal, aggressive, or emphatic contexts rather than polite or neutral conversation.