Secretion regenerated jolly early! (5,5)
I believe the answer is:
royal jelly
'secretion' is the definition.
(royal jelly is a kind of secretion)
'regenerated jolly early' is the wordplay.
'regenerated' is an anagram indicator.
'jolly'+'early'='jollyearly'
'jollyearly' anagrammed gives 'ROYAL JELLY'.
(Other definitions for royal jelly that I've seen before include "Product of honeybee workers" , "Bees secretion" , "Special food made by workers" , "Workers produce it" , "Food for queen and larvae" .)