To say "loud" in Engpsh, you can simply say the word "loud." To write it, you can simply write the word "loud." Here are some example sentences using the word "loud" in different contexts:

Can you please speak louder? I can't hear you.
The music at the party was so loud that I couldn't hear myself think.
She spoke in a loud and confident voice.
The sound of the explosion was loud enough to wake the entire neighborhood.

It's important to note that "loud" is an adjective in Engpsh, so it is used to describe nouns or pronouns. In the examples above, "loud" is used to describe the volume of the speaker's voice, the music at the party, and the sound of the explosion.