GU'AVA, noun An American tree, and its fruit, of the genus Psidium. It is of two species, or rather varieties, the pyriferum or white guava and pomiferum or red guava The fruit or berry is large and oval-shaped, like a pomegranate, which it resembles in its astringent quality. The pulp is of an agreeable flavor, and of this fruit is made a delicious jelly.