Publicly expose talent I've wasted (9)
I believe the answer is:
ventilate
'publicly expose' is the definition.
'talent i've wasted' is the wordplay.
'wasted' is an anagram indicator.
'talent'+'ive'='talentive'
'talentive' with letters rearranged gives 'VENTILATE'.
(Other definitions for ventilate that I've seen before include "Fan" , "Let air enter and circulate" , "Allow fresh air to circulate" , "Expose to a current of fresh air" , "Superficial" .)