citric adj.

any tree of the genus Citrus, or its fruit, 1825, from the Modern Latin genus name, from Latin citrus "citron tree," the 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] or from a lost non-IE Mediterranean language [de Vaan]. But Klein and others trace it to Greek kedros "cedar," perhaps via Etruscan (a suggested by the change of -dr- to -tr-).

Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).

In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.

"salt of citric acid," 1794, from French citrate; see citric + -ate (3).