pine·ap·ple / ˈpīˌnapəl/ • n. 1. a large juicy tropical fruit consisting of aromatic edible yellow flesh surrounded by a tough segmented skin and topped with a tuft of stiff leaves. 2. the widely cultivated tropical American plant (Ananas comosus, family Bromeliaceae) that bears this fruit. It is low-growing, with a spiral of spiny sword-shaped leaves on a thick stem. 3. inf. a hand grenade.