Flower rook brought into shelter (5)
I believe the answer is:
trent
'flower' is the definition.
(I've seen this before)
'rook brought into shelter' is the wordplay.
'rook' becomes 'r' (abbreviation in chess).
'brought into' indicates putting letters inside.
'shelter' becomes 'tent' (tent is a kind of shelter).
'r' placed within 'tent' is 'TRENT'.
(Other definitions for trent that I've seen before include "Crossword frame" , "Eng. river; Council of -" , "Main river of the Midlands" , "Major river of England" , "River through Newark" .)