Did you notice how many of these words have internal rhymes? Shūchū, muchū, and another muchū. There’s a different-sounding rhyme inside another 中 word:
中高 (nakadaka: convex) middle + high
This compound can also be read as chūkō, meaning “middle and high school” or “medium and high (level).” But as nakadaka, it’s “convex.” And just as a typical nose is convex, 中高 (nakadaka) can refer to a high, straight, centered nose, a feature that the Japanese consider beautiful.
Nakadaka—a word to roll off your tongue as frequently as possible! Somehow, it reminds me of “lucky duck”!