Silly spring flower (5)
I believe the answer is:
daffy
This clue is a double definition.
'silly' is the first definition.
(thesaurus)
'spring flower' is the second definition.
(short for daffodil)
(Other definitions for daffy that I've seen before include "Silly, eccentric (colloq.)" , "duck on screen" , "Bonkers" , "foolish" , "Cuckoo" .)