Fix me up with piece of furniture (5)
I believe the answer is:
embed
'fix' is the definition.
(I've seen this before)
'me up with piece of furniture' is the wordplay.
'up' is a reversal indicator (in down clue: letters go upwards).
'with' says to put letters next to each other.
'piece of furniture' becomes 'bed' (bed is a kind of piece of furniture**).
'me' back-to-front is 'em'.
'em'+'bed'='EMBED'
(Other definitions for embed that I've seen before include "Fix firmly and deeply" , "Firmly put down" , "Plant firmly" , "Surround" , "Put entirely inside something else" .)