Poet has house by river (5)
I believe the answer is:
homer
'poet' is the definition.
(I know that Homer is an poet)
'house by river' is the wordplay.
'house' becomes 'home' (homing is a kind of housing).
'by' is a charade indicator (letters next to each other).
'river' becomes 'r' (abbreviation for river).
'home'+'r'='HOMER'
'has' acts as a link.
(Other definitions for homer that I've seen before include "Great Greek who wrote The Iliad" , "Blind man" , "Weak official" , "Bird" , "Ancient Greek poet" .)