Wants dress with inside taken out before wedding begins (5)
I believe the answer is:
needs
'wants' is the definition.
(needing is a kind of wanting)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for needs that I've seen before include "Requires, is in want of" , "Calls for" , "Requirements" , "Requires or lacks" , "necessity once" .)