Refuse to admit study leads to faulty conclusion (4)
I believe the answer is:
deny
'refuse to admit' is the definition.
(thesaurus)
'study leads to faulty conclusion' is the wordplay.
'study leads' becomes 'den' (I can't justify this - if you can you should believe this answer much more).
'conclusion' indicates one should take the final letters.
The last letter of 'faulty' is 'y'.
'den'+'y'='DENY'
Can you help me to learn more?
(Other definitions for deny that I've seen before include "contest" , "Refuse to grant" , "Refuse to admit (something)" , "Gainsay" , "Refuse; repudiate" .)