water under the bridge
Water under the bridge (noun phrase) means something unpleasant that happened in the past and is no longer worth being upset about. Example: “We fell out badly in our twenties, but it's all water under the bridge now.”
How to use water under the bridge
Learner’s notesIn plain EnglishAn old problem that nobody minds about any more.
Idiomatic and neutral; treated as uncountable, so say "it's water under the bridge", never "a water under the bridge". Usually said by the injured party as a signal that they have let it go.
The image is of water that has flowed past and cannot come back — the point is that it is gone, not that it was unimportant.
Fill the gap
Can you complete this real example?
We fell out badly in our twenties, but it's all _____ now.