citrus (adj.)

1825, from Modern Latin genus name, from Latin citrus "citron tree," name of an African tree with aromatic wood and lemon-like fruit, the first citrus fruit to become available in the West. The name, like the tree, is probably of Asiatic origin [OED]. But Klein traces it to Greek kedros "cedar," and writes that the change of -dr- to -tr- shows that the word came from Greek into Latin through the medium of the Etruscans. As a noun, "tree of the genus Citrus," from 1885.