Exhibit old attitude (6)
I believe the answer is:
expose
'exhibit' is the definition.
(I know that exhibit can be written as expose)
'old attitude' is the wordplay.
'old' becomes 'ex' (prefix meaning former or onetime).
'attitude' becomes 'pose' (attitude can mean a pose or stance).
'ex'+'pose'='EXPOSE'
(Other definitions for expose that I've seen before include "Lay out to view" , "Disclose" , "outing" , "Uncover or unmask" , "Bring to light" .)