means The savory, mouth-filling taste—distinct from sweet, sour, salty, and bitter—produced by glutamates in foods like aged cheese, ripe tomatoes, mushrooms, soy sauce, and broth.

from Straight from Japanese: umai (delicious) plus mi (taste), so literally 'delicious taste.' The concept was named in the early 20th century by chemist Kikunae Ikeda, who tracked the haunting savoriness of kombu seaweed broth to glutamic acid—a discovery that launched MSG. The word only entered wide English use much later, once Western science finally accepted that the tongue counts to five.