Crossword Genius

After vacation, dress code ignored in ball outfit (6)

Ross

I believe the answer is:

livery

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'outfit' is the definition.
(thesaurus)

I don't understand the remainder of the clue.

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(Other definitions for livery that I've seen before include "Distinctive uniform once worn by servants of posh people" , "Uniform worn by male servants" , "Uniform -- suffering from gastric distress" , "The care of horses for pay" , "Feeding and stabling of horses for money" .)

I've seen this clue in The Hindu.
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