A lime (from French lime, from Arabic līma, from Persian līm, "lemon") is a hybrid citrus fruit, which is typically round, lime green, 1.2–2.4 inches in diameter, and containing acidic juice vesicles. There are several species of citrus trees whose fruits are called limes, including the Key lime (Citrus aurantifolia), Persian lime, kaffir lime, and desert lime.

Limes are an excellent source of vitamin C, and are often used to accent the flavors of foods and beverages. They are grown year-round. Plants with fruit called "limes" have diverse genetic origins; limes do not form a monophyletic group.

As compared to lemons, limes contain less vitamin C, but the amount is still an excellent source, providing 35% of the Daily Value per 100 g serving. Limes are a good source of dietary fiber and contain numerous other nutrients in small quantities