Any of several tropical American plants, of the genus Capsicum, principally the species Capsicum annuum and Capsicum frutescens, that are cultivated as edible peppers.
The spicy fruit of the above plants, the bell pepper.
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.)