What does mistake mean?

From Longman Dictionary of Contemporary English mis‧take1 /məˈsteɪk/ ●●● S2 W2 noun 1 [ countable] something that has been done in the wrong way, or an opinion or statement that is incorrect → error mistake in We may have made a mistake in our calculations.

What does mistook mean?

verb (used with object),mis·took [mi-stook], mis·tak·en [mi-stey-kuhn], mis·tak·ing. to regard or identify wrongly as something or someone else: I mistook him for the mayor. to understand, interpret, or evaluate wrongly; misunderstand; misinterpret. verb (used without object),mis·took [mi-stook], mis·tak·en [mi-stey-kuhn], mis·tak·ing.

What does it mean if you say there is no mistaking something?

If you say there is no mistaking something, it is very clear or obvious. She may be unconventional but there's no mistaking her ability to run the company. There was no mistaking his determination. [=his determination was obvious] I mistook him for his brother. [=I thought that he was his brother]