fatalslip
nounUK /ˈfeɪ.təl slɪp/
US /ˈfeɪ.t̬əl slɪp/
A very bad mistake that cannot be fixed.
The knight made a fatal slip and lost the key to the castle.
OTHER MEANINGS
2. A slip or fall that causes death.
The hiker's fatal slip on the icy path was a tragedy.
3. A small error in a computer program that makes the whole system crash.
A fatal slip in the code shut down the game for everyone.
4. A wrong step in a dance or performance that ruins the whole show.
One fatal slip during the recital made the dancer forget the rest.