Cute sound?

LONGU

Think of a soft, drawn-out coo from a bird that rhymes with "wrong you."

The clue "Cute sound?" plays on the word "aww," the noise people make when they see something adorable. But instead of spelling it normally, it’s written as "LONG U" (like the letter "U" stretched out—awww). So "LONG U" sounds like "longu," turning a sweet reaction into a clever, punny answer.