How can i make my cat stop meowing?

Get him a cat friend. Also a perch for him to look out of the window. Feed him his favorite food. get an aquarium of fish to watch (mine love it). Cat nip , scratching post.If all fails have him checked FIV may be painful, And most important, get him fixed. He may want to roam due to other cats in heat. Some cats are called "chatty cats". He might be one.