Flower rook dropped into red wine (5)
I believe the answer is:
trent
'flower' is the definition.
(I've seen this before)
'rook dropped into red wine' is the wordplay.
'rook' becomes 'r' (abbreviation in chess).
'dropped into' means one lot of letters goes inside another.
'red wine' becomes 'tent' (type of Spanish wine).
'r' inserted within 'tent' is 'TRENT'.
(Other definitions for trent that I've seen before include "Crossword frame" , "River that joins the Ouse to form the Humber" , "River at Newark/Stoke" , "Main river of the Midlands" , "Stoke's river" .)