One man's name for a kind of grass (7)
I believe the answer is:
timothy
I believe this clue is a double definition.
'one man's name' is the first definition.
(I've seen this before)
'a kind of grass' is the second definition.
(I know that timothy is a type of grass)
'for' acts as a link.
(Other definitions for timothy that I've seen before include "haymaker?" , "Bible book" , "Grass; saint" , "A grass; two NT books" , "young Cratchit at length?" .)