Having some deficiency outside (7)
I believe the answer is:
without
'outside' is the definition.
(thesaurus)
'having some deficiency' is the wordplay.
'having' becomes 'with' (I've seen this before).
'some deficiency' becomes 'out' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'with'+'out'='WITHOUT'
Can you help me to learn more?
(Other definitions for without that I've seen before include "Lacking; not inside" , "Free from: in the absence of" , "Not accompanied by" , "Lacking; outside" .)