kumquat
kumquat , noun
[Chin. kin keu.]
(Botany) any of several trees or shrubs of the genus Fortunella (formerly Citrus) of the rue family (Rutaceae) (especially Citrus Japonica) growing in China and Japan bearing small orange-colored edible fruits with thick sweet-flavored skin and sour pulp; also, any of the small acid, orange-colored citrus fruits of such plants, used mostly for preserves.