Millions laugh, talking about Blitz (9)
I believe the answer is:
onslaught
'blitz' is the definition.
(thesaurus)
'millions laugh talking about' is the wordplay.
'about' indicates the answer is hidden within the clue (the clue goes around or about the answer).
'ONSLAUGHT' is hidden within 'millions laugh talking'.
(Other definitions for onslaught that I've seen before include "Sudden and severe onset of trouble" , "Sally" , "Barrage" , "Hunt goals (anag) - offensive" , "offensive action" .)