Hawthorn blossom (3)
I believe the answer is:
may
'hawthorn blossom' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for may that I've seen before include "Girl's name; 10 ac (anag.)" , "Hawthorm blossom" , "plant that's tropical making comeback" , "The merry merry month( 3)" , "UK PM" .)