Table with a flower still to be put up outside (6)
I believe the answer is:
teapoy
'table' is the definition.
(I know that Teapoy is a type of table)
'a flower still to be put up outside' is the wordplay.
'flower' becomes 'Po' (Italian river).
'still' becomes 'yet' (yet can mean still or so far).
'to be put up' says the letters should be written backwards.
'outside' is an insertion indicator (some letters go outside others).
'yet' in reverse letter order is 'tey'.
'a'+'po'='apo'
'apo' going into 'tey' is 'TEAPOY'.
'with' acts as a link.
(Other definitions for teapoy that I've seen before include "Ornamental three-legged stand, with caddie" , "Three-legged stand for a tea-caddy" .)