Final answer:
The figure of speech 'a slip of the tongue' means making an unintentional mistake in speech, speaking something different from what was intended.
Step-by-step explanation:
The figure of speech 'a slip of the tongue' means making an unintentional mistake in speech, speaking something different from what was intended. It is often used to describe a momentary lapse or error in language. Similar to a literal slip, when one's foot accidentally loses traction, a slip of the tongue is when someone's words accidentally lose control. It can lead to funny or embarrassing situations. For example, if someone is trying to say 'I love you' but accidentally says 'I loathe you,' it would be considered a slip of the tongue.