N-COUNT
（常指难以应付的）大批，大量
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.
例句
The onslaught of orders should keep aircraft manufacturers busy for some time.
纷至沓来的订单应该会让飞机制造商忙碌一段时间。
...the constant onslaught of ads on American TV.
美国电视上让人应接不暇的广告