Employed a large earthmover but the beast dropped off (9)

I believe the answer is:

bulldozed

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

'employed a large earthmover' is the definition.
Although both the answer and definition are past participle verbs, I can't understand how one could define the other.

'the beast dropped off' is the wordplay.
'the beast' becomes 'bull' (bull is a kind of beast).
'dropped off' becomes 'dozed' (I've seen this in another clue).
'bull'+'dozed'='BULLDOZED'

'but' is the link.

Can you help me to learn more?

(Another definition for bulldozed that I've seen is " flattened".)

I've seen this clue in the Sydney Morning Herald.

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.