(onslaughts)
1.
An onslaught on someone or something is a very violent, forceful attack against them.
The rebels responded to a military onslaught against them by launching a major assault on an army camp.
= assault
N-COUNT: usu with supp, oft N on/against n, N by n
2.
If you refer to an onslaught of something, you mean that there is a large amount of it, often so that it is very difficult to deal with.
...the constant onslaught of ads on American TV.
= barrage
N-COUNT: usu N of n