"ovate, pale yellow citrus fruit," c. 1400, lymon, from Old French limon "citrus fruit" (12c.), which comes via Provençal or Italian from Arabic laimun, Persian limun. Apparently brought from India to the Levant by the Arabs 9c. or 10c.; the word is perhaps ultimately from an Austronesian word of the Malay archipelago, such as Balinese limo "lemon," Malay limaw "citrus fruit, lime" (compare lime (n.2)).

Meaning "person with a tart disposition" is from 1863. For the sense "worthless thing," see lemon (n.2). Slang meaning "a Quaalude" is 1960s, from Lemmon, name of a pharmaceutical company that once manufactured the drug. The surname is from Middle English leman "sweetheart, lover." Lemon-juice is attested from 1610s; the candy lemon-drop from 1807. The East Indian lemon-grass (1837) is so called for its smell.

"worthless thing, disappointment, booby prize," 1909, American English slang; from lemon (n.1), perhaps via a criminal slang sense of "a person who is a loser, a simpleton," perhaps an image of someone a sharper can "suck the juice out of." A pool hall hustle was called a lemon game (1908); while to hand someone a lemon was British slang (1906) for "to pass off a sub-standard article as a good one." Or it simply may be a metaphor for something which leaves a bad taste in one's mouth. Specific sense of "second-hand car in poor condition" is by 1931.

1767 (implied in lemoned), from lemon (n.1).

"large, thick-rinded, lemon-like citrus fruit," late 14c., also citrine (early 15c.), from Old French citron "citron, lemon" (14c.), possibly from Old Provençal citron, from Latin citrus "citron-tree," and influenced by lemon; or else from augmentative of Latin citreum (mālum) "citron (apple);" see citrus.

Apparently the citron was the only citrus fruit known to the Greeks and Romans; the word was used in English to also mean "lemon" or "lime" until the sense became restricted 17c.

"resembling or infused with lemon," 1846, from lemon (n.1) + -y (2). In Australia/New Zealand slang, also "irritated, angry" (1941). An earlier adjective was lemonish (1719).

1858 in reference to a type of fragrant grass, and especially to the oil it yields, from French citronelle "lemon liquor," from citron (see citrus). Originally an Asiatic grass used in perfumes and soaps, later applied to a substance found in lemon oil, etc. Related: Citronellic.

1650s, nativized from French limonade, limonnade (1560s), which is from Italian limonata or else a French formation from limon; see lemon (n.1) + -ade. The earlier English spelling was lemonado (c. 1640) with false Spanish ending.

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-).

"lemon-colored, yellow or greenish-yellow," late 14c., from French citrin, from Latin citrus (see citrus). From 1879 as a color name.

1670s, from French zeste "piece of orange or lemon peel used as a flavoring," of unknown origin. Sense of "thing that adds flavor" is 1709; that of "keen enjoyment" first attested 1791.