Definite volume refers to something which has a consistent, unchanging volume, which in practical terms may mean a static mass and density, or a predetermined shape, either of which will dictate volume. A cube with side length l has a definite volume because it can only be exactly one size.
One cup of raw plantains or one medium sized raw plantain contains: ~180-200 calories, 0.5 g total fat, 47-50 g carbohydrates, 3.5 g dietary fiber, 22 g sugar and 2 g protein. Because of it's high carbohydrate content, you need to monitor your portion, otherwise your blood sugars will spike.
Plantain is a perennial weed with almost worldwide distribution. There are about 250 species. P. lanceolata and P. major are among the most widely distributed, and they grow aggressively. Plantain is wind-pollinated, facilitating its growth where there are no bees and few other plantain plants. P. major produces 13,000 to 15,000 seeds per plant, and the seeds have been reported to remain viable in soil for up to 60 years. P. lanceolata produces 2,500 to 10,000 seeds per plant and has a somewhat shorter seed viability. Plantain seeds can survive passage through the gut of birds and other animals, facilitating their distribution.