Grass-like plant (5)
I believe the answer is:
sedge
'grass-like plant' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for sedge that I've seen before include "water-loving vegetation" , "Marsh grass" , "Bog plant; type of warbler" , "Herons" , "Wetland grass-like plant" .)