High season for the children? (9)
I believe the answer is:
offspring
'the children?' is the definition.
(thesaurus)
'high season' is the wordplay.
'high' becomes 'off' (I've seen this in other clues).
'season' becomes 'spring' (spring is a kind of season).
'off'+'spring'='OFFSPRING'
'for' acts as a link.
(Other definitions for offspring that I've seen before include "Issue for raising" , "Child" , "Kids" , "Young" , "Result" .)