Reveal an outdated attitude (6)
I believe the answer is:
expose
'reveal' is the definition.
(exposing is a kind of revealing)
'an outdated attitude' is the wordplay.
'an outdated' becomes 'ex' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'attitude' becomes 'pose' (attitude can mean a pose or stance).
'ex'+'pose'='EXPOSE'
Can you help me to learn more?
(Other definitions for expose that I've seen before include "Lay out to view" , "Reveal, uncover" , "outing" , "Reveal or unmask" , "Disclose" .)