Superficial bogus theory ignoring the odds (5)
I believe the answer is:
outer
'superficial' is the definition.
(thesaurus)
'bogus theory ignoring the odds' is the wordplay.
'ignoring the odds' means one should take alternating letters (letters in odd-numbered positions are removed).
'bogus'+'theory'='bogustheory'
The alternating letters of 'bogustheory' are 'OUTER'.
(Other definitions for outer that I've seen before include "External kind of route" , "Ring for double scores on a dartboard" , "This space is beyond earth's atmosphere" , "Objective" , "External; part of archery target" .)