It grows wild in May (3)
I believe the answer is:
yam
'it grows wild' is the definition.
The definition suggests a singular noun which matches the answer.
'may' is the wordplay.
'may' can be anagrammed to 'YAM'.
However, I'm not sure how this is indicated.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for yam that I've seen before include "Edible tuber" , "Tropical climber" , "US sweet-potato" , "American sweet potato" , "Tuberous vegetable" .)
