slip of the tongue; verbal mistake
Refers to an unintentional error in speaking, such as mispronouncing a word or saying the wrong thing.
I made a slip of the tongue during the speech.
That was just a verbal slip-up.
Implies a more serious or embarrassing verbal gaffe, often with social consequences.
Compound of 言い (the continuative form of 言う 'to say') and 間違い 'mistake'.