The one preparing to imprison dissolute chancer (6,8)

I believe the answer is:

prince charming

I'm a little stuck... Click here to teach me more about this clue!

'the one' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.

'preparing to imprison dissolute chancer' is the wordplay.
'preparing' becomes 'priming' (priming is a kind of preparing).
'to imprison' indicates putting letters inside.
'dissolute' indicates an anagram.
'chancer' is an anagram of 'ncechar'.
'priming' going around 'ncechar' is 'PRINCE CHARMING'.

Can you help me to learn more?

(Another definition for prince charming that I've seen is " Dishy bloke".)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.