Somewhat dim or talentless human being (6)
I believe the answer is:
mortal
'human being' is the definition.
(as opposed to a god or immortal)
'somewhat dim or talentless' is the wordplay.
'somewhat' says the answer is hidden in the clue.
'MORTAL' is hidden within 'dim or talentless'.
(Other definitions for mortal that I've seen before include "Subject to death, like all mankind" , "Causing death" , "Sound a wound is deadly" , "Very drunk < person" , "Destined to die" .)