Definition & Meaning of "[be] on the tip of {one's} tongue"

What is the origin of the idiom "on the tip of one's tongue" and when to use it?

The idiom "on the tip of one's tongue" has an origin rooted in the physical sensation people experience when they are trying to recall a specific word or piece of information. When someone is very close to remembering something but cannot quite articulate it, they may feel a sensation of the word or idea being almost within reach, as if it is poised right at the tip of their tongue. This idiom is commonly used when someone is trying to remember or mention something but has not yet succeeded in doing so.