Water finally put on cheese plant (5)
I believe the answer is:
brier
'plant' is the definition.
(brier is a kind of plant)
'water finally put on cheese' is the wordplay.
'finally' says to take the final letters.
'put on' is a charade indicator (letters next to each other).
'cheese' becomes 'brie' (Brie is an example**).
The last letter of 'water' is 'r'.
'r' put after 'brie' is 'BRIER'.
(Other definitions for brier that I've seen before include "plant" , "Prickly shrub" , "smoking pipe" , "Thorny bush like the wild rose" , "It may be smoked" .)