The antonym of “loudly” is “softly.” “Loudly” is an adverb that describes the manner in which something is done, while “softly” is an adverb that describes the manner in which something is done in a quiet or gentle way.
The importance of using antonyms is that they allow us to express our thoughts and ideas in a more precise and nuanced way. By using the antonym of “loudly,” we can more clearly convey the idea of something being done in a quiet or gentle way.