Assuming you have correct crossing letters (I don't have the crossword and have no reason to suspect otherwise), I think the answer must be inane
An explanation might be:
'inane' = 'empty'.
'in a' = 'part of a'
'en' backwards = 'ne'; 'en' prefixes words such as 'enclose' and could give the meaning of (to) 'house'. Alternatively, 'EN' = 'Enrolled Nurse' and maybe this is what is meant by the term 'House Nurse'?