Any fruit of a plant of the botanical genus Capsicum, which has a spicy/burning flavour because it contains capsaicin. (Not all chili peppers are particularly spicy, but all true chili peppers contain some capsaicin, in contrast to e.g. the bell pepper, which is not a true chili pepper and does not.)
The flowering vine Piper longum in the genus Piper (pepper) of family Piperaceae, cultivated for its characteristically long fruit, which is usually dried and used as a spice and seasoning.