To say the verb "to meow" in Japanese, you would use naku 鳴く, which means "(for an animal) to make a sound," i.e. "to cry." Observe:
neko wa "nyaa" to naku 猫は「にゃあ」と鳴く Cats make the sound "meow." Cats meow "meow."
inu wa "wan" to naku 犬は「わん」と鳴く Dogs make the sound "woof." Dogs bark "woof."
This isn't to be confused with the homonym naku 泣く, which means "to cry (tears)," instead.