floodgate
Concise Oxford English Dictionary © 2008 Oxford University Press:
floodgate/ˈflʌdɡeɪt/
▶noun
- 1 a gate that can be opened or closed to admit or exclude water, especially the lower gate of a lock.
- 2 (the floodgates) last restraints holding back a powerful outpouring.
'floodgate' also found in these Oxford entries:

