Close look for a costume? (5,6)
I believe the answer is:
strip search
'a costume?' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'close look for' is the wordplay.
'close' becomes 'strip' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'look for' becomes 'search' (synonyms).
'strip'+'search'='STRIP-SEARCH'
Can you help me to learn more?
(Other definitions for strip search that I've seen before include "personal inspection" , "examination" , "attempt to find hidden items" , "Intimate inspection by officers" , "intimate investigation" .)