DJ cross during day before party (6)
I believe the answer is:
tuxedo
'dj' is the definition.
(I've seen this before)
'cross during day before party' is the wordplay.
'cross' becomes 'x' (an X is a cross).
'during' means one lot of letters goes inside another.
'day before' becomes 'tue' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'party' becomes 'do' (do can informally mean a party).
'x' placed inside 'tue' is 'tuxe'.
'tuxe'+'do'='TUXEDO'
Can you help me to learn more?
(Other definitions for tuxedo that I've seen before include "An American monkey-suit" , "American DJ" , "Dinner jacket (US)" , "American dinner jacket" , "Garment" .)