Canonical clue

In crossword lore, a canonical clue is a certain clue or set of similar clues which has become "standard" through frequent republication, usually being the most concise or immediately apparent for a particular word.

Examples

 * Prison riot (4), a double definition for the word STIR, has been printed so many times in major daily cryptics that other clues, barring the occasional minor variation, are extremely seldom seen.