Any of various evergreen, usually spiny shrubs or trees of the genus Citrus, such as the grapefruit, lemon, or orange, native to southern and southeast Asia, having leathery, aromatic, unifoliolate compound leaves and widely cultivated for their juicy edible fruits that have a leathery aromatic rind.
The fruit of any of these plants.
adj. Of or relating to any of the citrus plants or their fruits.
(sĭt'rəs) 