500 on ship wear formal clothes (5)

I believe the answer is:

dress

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'wear formal clothes' is the definition.
'dress' can be an answer for 'wear' (both can mean a person's clothing). I am not certain of the 'formal clothes' bit.

'500 on ship' is the wordplay.
'500' becomes 'D' (Roman numeral for 500).
'on' becomes 're' ('on' can be mean 'with reference to').
'ship' becomes 'SS' (prefix in ship names eg SS Great Britain).
'd'+'re'+'ss'='DRESS'

Can you help me to learn more?

(Other definitions for dress that I've seen before include "Uniform" , "Garb" , "Apparel" , "This woman might slip on" , "get into gear" .)

I've seen this clue in The Sun.

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