Complaint from youth in spring month (6)
I believe the answer is:
malady
'complaint' is the definition.
(thesaurus)
'youth in spring month' is the wordplay.
'youth' becomes 'lad' (I've seen this before).
'in' is an insertion indicator.
'spring month' becomes 'may' (May is a spring month).
'lad' going inside 'may' is 'MALADY'.
'from' is the link.
(Other definitions for malady that I've seen before include "Ailment; illness" , "Disease, ailment" , "Sickness or disease" , "affection" , "hay fever, perhaps" .)