A key plant, for a time (6)
I believe the answer is:
easter
'a time' is the definition.
The definition and answer can be both related to time as well as being singular nouns.
Maybe there's a link between them I don't understand?
'a key plant' is the wordplay.
'a key' becomes 'e' (I've seen this in other clues).
'plant' becomes 'aster' (aster is a kind of plant).
'e'+'aster'='EASTER'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for easter that I've seen before include "Main Christian festival" , "Festival after Lent" , "Teaser (anag.)" , "holiday time" , "Christian festival in Spring" .)