まったmattaku
1.

An adverb used to emphasize the extent to which something is true or complete, often suggesting an overwhelming degree of affirmation or agreement with a statement or situation.

2.

A phrase expressing a total absence, frequently utilized in negative contexts to strongly deny or refute the possibility of something being true.

3.

An expression that communicates a sense of thoroughness or totality, indicating that something has been entirely or completely transformed or achieved, without any exception.

Example:

彼の意見は我々の意見とはまったく違っている。