Cut outside crate, otherwise cut inside (9)
I believe the answer is:
gatecrash
'cut outside crate otherwise cut inside' is the definition.
I can't tell whether this defines the answer.
'crate otherwise cut inside' is the wordplay.
'otherwise' is an anagram indicator.
'cut' becomes 'gash' (a gash is a wound or cut).
'inside' is an insertion indicator.
'crate' anagrammed gives 'atecr'.
'atecr' put into 'gash' is 'GATECRASH'.
Can you help me to learn more?
(Other definitions for gatecrash that I've seen before include "to do so uninvited" , "enter without invitation" , "join party unofficially" , "Try to get in for free" , "join party if not wanted" .)