floodgate
/ˈflʌdgeɪt/noun
1- a gate that can be opened or closed to admit or exclude water, especially the lower gate of a lock（尤指下层）泄洪闸门, （泄）水闸门。
1.1
- figurative （一般作the floodgates）a last restraint holding back an outpouring of something powerful or substantial〈喻〉最后一道闸门; 最终的制约措施：
his lawsuit could open the floodgates for thousands of similar claims.
他的诉讼案将会打开无数同类索赔的闸门。