Indicate one's willingness to remove the top from the moneybox (5)

I believe the answer is:

offer

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

'indicate one's willingness to remove the top' is the definition.
I can't judge whether this definition defines the answer.

'from the moneybox' is the wordplay.
'from' becomes 'off' (eg someone might be from or 'off' a TV show).
'the moneybox' becomes 'er' (I can't justify this - if you can you should believe this answer much more).
'off'+'er'='OFFER'

Can you help me to learn more?

(Other definitions for offer that I've seen before include "Tender for acceptance" , "Make available for sale" , "Proposal (of marriage)" , "Suggest" , "Tender, volunteer" .)

I've seen this clue in The Irish Independent.

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.