What is the meaning of the idiom "slip of tongue"?

The idiom "slip of the tongue" means a mistake of speech. It is a common expression that is used to describe when someone says something that they did not mean to say. This can happen for a variety of reasons, such as:

• Mispronouncing a word: For example, you might say "I'm going to the park to get some milk" when you meant to say "ice cream."
• Using the wrong word: For example, you might say "I'm so hungry, I could eat a horse" when you meant to say "I could eat a horse's leg."
• Confusing two words: For example, you might say "I'm going to the bank to deposit some money" when you meant to say "I'm going to the store to deposit some money."