Know the man is back in the dog-house (6)
I believe the answer is:
kennel
'the dog-house' is the definition.
(I've seen this before)
'know the man is back' is the wordplay.
'know' becomes 'ken' (I've seen this in another clue).
'the man' becomes 'len' (short for Leonard).
'is back' shows that the letters should be reversed in order.
'len' written backwards gives 'nel'.
'ken'+'nel'='KENNEL'
'in' acts as a link.
(Other definitions for kennel that I've seen before include "Dog's shelter" , "Snoopy slept atop it" , "Home for the dog" , "Dog shelter" , "Canine boarding place" .)