What is an antonym for intonation?

There isn't a perfect antonym for "intonation" because it has a specific meaning related to the rise and fall of the voice. However, depending on the context, some words that could be considered opposite in meaning include:

* Monotone: This refers to a flat, unchanging tone of voice, the opposite of the varied pitch of intonation.

* Apathy: While not directly related to vocal delivery, apathy suggests a lack of emotional investment in speech, the opposite of the emphasis and feeling conveyed through intonation.

* Flatness: This describes a lack of expressiveness, which is a key element of intonation.

* Uninflected: This term describes speech lacking in the rises and falls characteristic of intonation.

It's important to consider the specific context when choosing a word to convey the opposite of "intonation."