Dwelling hard by river (5)
I believe the answer is:
house
'dwelling' is the definition.
(I know that House is a dwelling)
'hard by river' is the wordplay.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'by' says to put letters next to each other.
'river' becomes 'ouse' (Yorkshire river).
'h'+'ouse'='HOUSE'
(Other definitions for house that I've seen before include "Inn" , "Leo, say" , "See 18" , "Theatre audience - dwelling" , "Dwelling, living quarters (5)" .)