The word "coolwart" is an archaic term for a type of plant called "colewort" or "kale." Its spelling may seem confusing, but it follows the standard English pronunciation rules. "Coolwart" is pronounced as /kuːlwərt/, with the "oo" sound being a long vowel, the "l" is silent and the "a" is pronounced like "uh." The word's spelling showcases the evolution of the English language and is a reminder of the diversity of dialects and accents within the language.