Definition
To initiate a situation that permits a large number of similar events or actions to occur, often uncontrollably, that were previously limited or restricted.
一发不可收拾
This ruling could open the floodgates for future lawsuits.
这项裁决可能会为未来的诉讼打开闸门。
Once they started offering free samples, it opened the floodgates to giveaways.
一旦他们开始提供免费样品，就开启了赠品的大门。
The new immigration policy could open the floodgates for an influx of unauthorized immigrants.
新的移民政策可能会为非法移民的涌入打开闸门。