Why the phrase which means confess or admit guilt is not defined as such in English dictionaries?

You're right, the phrase "confess or admit guilt" isn't a single, established term in English dictionaries. That's because it's a more nuanced concept that combines two separate actions:

* Confess: This implies acknowledging a wrongdoing or a crime, often with the intention of seeking forgiveness or leniency. It's a more formal and serious action, often associated with legal or religious contexts.

* Admit guilt: This is a broader acknowledgment of responsibility for something, regardless of whether it's considered a crime or not. It can encompass personal failings, mistakes, or errors in judgment.

While the phrases have some overlap, they are not interchangeable in every situation. Therefore, dictionaries don't define them as a single phrase because they represent distinct actions with slightly different implications.

However, you can find definitions for both "confess" and "admit guilt" individually in dictionaries.