Other forms: onslaughts
An onslaught is a fierce sustained attack. Withstand the onslaught, an onslaught of criticism, the enemy onslaught.
The figurative use is the commoner now: an onslaught of emails or of criticism is more than can be dealt with. The word is not from slaughter but from a Dutch compound meaning a striking at.
1nounonslaughtA fierce sustained attack.
“The small boat could not survive the onslaught of the waves.”
onslaught is an attack.
From a Middle Dutch compound meaning a striking at, later reshaped in English towards slaughter.
Middle Dutch
aenslag
English, today
onslaught
From on- + slaught. Formed after Middle Dutch aenslag, aenslach, equivalent to aen + slag, although slaught corresponds to slacht; slag is cognate with the English weaving term sley. Compare Dutch aanslag and German Anschlag.
Etymology from Wiktionary, CC BY-SA