Charmed in brief period before spring (10)
I believe the answer is:
spellbound
'charmed' is the definition.
(spellbinding is a kind of charming)
'brief period before spring' is the wordplay.
'brief period' becomes 'spell' (I've seen this in another clue).
'before' is a charade indicator (letters next to each other).
'spring' becomes 'bound' (synonyms).
'spell'+'bound'='SPELLBOUND'
'in' acts as a link.
(Other definitions for spellbound that I've seen before include "frozen" , "Fascinated" , "attending solidly" , "appear hypnotised" , "Transfixed, mesmerised" .)