Citrus decumana

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Also see: Citrus | decumana

Concise Oxford English Dictionary © 2008 Oxford University Press:
citrus/ˈsɪtrəs/

▶noun (pl. citruses)

• 1 a tree of a genus that includes citron, lemon, lime, orange, and grapefruit. [Genus Citrus.]

• 2 (also citrus fruit) a fruit from a citrus tree.

– derivatives
citrous adjective,
citrusy adjective.

– origin L., ‘citron tree, thuja’.