Flower on a cheek (4)
I believe the answer is:
tear
'flower on a cheek' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tear that I've seen before include "Droplet; rip" , "Rend; travel in haste" , "Rip, sever roughly" , "Lacerate - sign of sorrow" , "A drop of optical moisture" .)