Crossword Genius

Sink money wearing formal top (6)

Ross

I believe the answer is:

invest

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

'sink money' is the definition.
'invest' can be an answer for 'sink' (I've seen this before). I am not certain of the 'money' bit.

'wearing formal top' is the wordplay.
'wearing' becomes 'in' (as in being 'in' certain clothes).
'formal top' becomes 'vest' (I've seen this before. I am not sure about the 'formal' bit.).
'in'+'vest'='INVEST'

Can you help me to learn more?

(Other definitions for invest that I've seen before include "Put money into a company" , "Put money into in hopes of a return" , "Lay siege" , "Play the market" , "Lay out in expectation of profit" .)

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