Airhead doctor encountered in life? (5)
I believe the answer is:
bimbo
'airhead' is the definition.
(both can mean a stupid person)
'doctor encountered in life?' is the wordplay.
'doctor' becomes 'MB' (Bachelor of Medicine, Medicinae Baccalaureus).
'encountered in' means one lot of letters goes inside another.
'life?' becomes 'bio' (life can mean a biography).
'mb' inserted into 'bio' is 'BIMBO'.
(Other definitions for bimbo that I've seen before include "Attractive but vacant young woman" , "floozie?" , "Scornful slang term for attractive but unintelligent young woman" , "Attractive but empty-headed young female" , "empty cracker?" .)