lock the barn door after the horse has bolted
idiomPart ofbarn
lock the barn door after the horse has bolted — idiom
1. to act only after the harm has already been done, when the action cannot really
1.idiom
Definition
to act only after the harm has already been done, when the action cannot really help.
Example
Changing the password after the money was stolen was locking the barn door after the horse had bolted.
After three crashes, the new warning signs felt like locking the barn door after the horse had bolted.