One nailed to back of house (3)
I believe the answer is:
toe
'one nailed' is the definition.
I can't judge whether this definition defines the answer.
'to back of house' is the wordplay.
'back of' indicates one should take the final letters.
The last letter of 'house' is 'e'.
'to'+'e'='TOE'
Can you help me to learn more?
(Other definitions for toe that I've seen before include "'Little piggy'" , "Digit; kick" , "Pedal extremity" , "Lower digit" , "A foot division" .)