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.
The Latin word for mistake is error
mistake=err
The correct spelling is all one word "mistake" (error).