Definition & Meaning of "face that (would|could) stop a clock"

What is the origin of the idiom "face would stop a clock" and when to use it?

The origin of the phrase "face would stop a clock" is unclear, but it is believed to have originated as playfully suggesting that the sight of the person's face is so visually striking or unpleasant that it could stop the movement of a clock. It is used to humorously describe someone's appearance as exceptionally unattractive or attention-grabbing. The idiom is not meant to be taken literally and is used for comedic effect. However, it's important to exercise caution when using this idiom, as it can be considered offensive or hurtful to the person being referred to. The idiom "a face that would stop a clock" can be considered somewhat old-fashioned. While it may still be used in certain contexts, it is not as commonly heard in modern everyday conversations.