In one's own house (2,4)
I believe the answer is:
'in one's own house' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for at home that I've seen before include "In (for a party?)" , "ready to receive visitors" , "Reception in one's own abode" , "Where one lives" , "In one's own house" .)