Hardly Osama's favourite uncle! (3)
I believe the answer is:
sam
'uncle' is the definition.
(Uncle Sam is an example)
'hardly osama's favourite' is the wordplay.
'SAM' is hidden within the letters.
But, I am not sure how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for sam that I've seen before include "Boy" , "Casablanca piano player" , "Uncle" , "together once" .)