Very popular children's game, English classic (7)
I believe the answer is:
vintage
'classic' is the definition.
(thesaurus)
'very popular children's game english' is the wordplay.
'very' becomes 'v' (abbreviation).
'popular' becomes 'in'.
'children's game' becomes 'tag' (I've seen this before).
'english' becomes 'e' (abbreviation).
'v'+'in'+'tag'+'e'='VINTAGE'
(Other definitions for vintage that I've seen before include "Date of origin (of wine etc)" , "Type of wine" , "Period of origin" , "Describing cars built between 1919 and 1930" , "Wine of a good year" .)