oops
One was a mistake that caused a catastrophe and one was not a mistake
The word for revealing one's innermost intentions by mistake is "inadvertently."
A blunder is a foolish mistake.
Yes it was a mistake because it caused World War 2
Error,Mishap
About one-half of unintended pregnancies are caused by contraceptive failure, either a failure of the method or a mistake by the user
Here: You made a mistake spelling the word "sentence."
The word mistake is an abstract noun, a word for an error in action or judgement.
Mistake, error, goof, blunder, miscalculation, misstep.
In the war, one of my shots rebounded into your head by mistake.
The correct spelling is all one word "mistake" (error).
The Latin word for mistake is error