Terrible costumes for vices (3,6)

I believe the answer is:

bad habits

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'vices' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'terrible costumes' is the wordplay.
'terrible' becomes 'bad' (similar in meaning).
'costumes' becomes 'habits' (I can't justify this - if you can you should believe this answer much more).
'bad'+'habits'='BAD HABITS'

'for' is the link.

Can you help me to learn more?

I've seen this clue in The Mirror.

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