onslaught
Concise Oxford English Dictionary © 2008 Oxford University Press:
onslaught/ˈɒnslɔːt/
▶noun a fierce or destructive attack.
■ an overwhelmingly large quantity of people or things.
– origin C17 (also as anslaight): from MDu. aenslag, from aen ‘on’ + slag ‘blow’, assoc. with obs. slaught ‘slaughter’.
'onslaught' also found in these Oxford entries:

