what is a moomoo gown

A "moomoo gown" is likely a misspelling of "muumuu gown," which is a loose dress of Hawaiian origin that hangs from the shoulder and is like a cross between a shirt and a robe. Muumuus are usually long, light, airy, and unbelted, and they can be brightly colored with floral patterns or other Polynesian motifs. They are popular as maternity wear because they do not restrict the waist. Muumuus are also the preferred formal dress for weddings and festivals such as the Merrie Monarch hula competition. While "moomoo" and "moo moo" are incorrect spellings, "muumuu" is also acceptable in most other English-speaking languages.