Online Etymology Dictionary

general (n.): late 14c., "whole class of things or persons," from general (adj.). Meaning "commander of an army" is 1570s, shortening of captain general, from Middle French capitaine général. The English adjective was affixed to civic officer designations by late 14c. to indicate superior rank and extended jurisdiction.
generalisation (n.): chiefly British English spelling of generalization. For spelling, see -ize.
generalissimo (n.): 1620s, from Italian generalissimo, superlative of generale, from a sense development similar to French general (see general (n.)).
generalist (n.): 1610s, from general (adj.) + -ist.
generality (n.): c.1400, from Old French generalité, from Latin generalitatem (nominative generalitas) "generality," from generalis (see general (adj.)). Related: Generalities. Form generalty is attested from late 14c.
generalization (n.): 1761, "act of generalizing," from generalize + -ation. Meaning "a general inference" is from 1794.
generalize (v.): 1751, probably a new formation from general (adj.) + -ize. Middle English had generalisen (early 15c.). Related: Generalizable; generalized; generalizing.
generally (adv.): "including everyone; in a general way, without reference to particulars," mid-14c., from general (adj.) + -ly (2).
generate (v.): c.1500, "to beget" (offspring), a back-formation from generation or else from Latin generatus, past participle of generare "to beget, produce" (see generation); originally "to beget;" in reference to natural forces, conditions, substances, etc., attested from 1560s. Related: Generated; generating.
generation (n.): early 14c., "body of individuals born about the same period" (usually 30 years), from Old French generacion (12c.) and directly from Latin generationem (nominative generatio) "generating, generation," noun of action from past participle stem of generare "bring forth" (see genus). Meanings "act or process of procreation," "process of being formed," "offspring of the same parent" are late 14c.

Generation gap first recorded 1967; generation x is 1991, from Douglas Coupland book of that name; generation y attested by 1994. Related: Generational. Adjectival phrase first-generation, second-generation, etc. with reference to U.S. immigrants is from 1896.
generative (adj.): early 15c., from generate + -ive. Use in linguistics is attested by 1959. Related: Generativity.
generator (n.): 1640s, "person or thing that generates," from Latin generator "a begetter, producer," agent noun from past participle stem of generare (see generation). Meaning "machine that generates power" first recorded 1794; in sense of "machine that generates electric energy," 1879. Fem. generatrix attested from 1650s.
generic (adj.): 1670s, "belonging to a large group of objects," formed in English from Latin gener-, stem of genus "kind" (see genus) + -ic. Sense of "not special, not brand-name; in plain, cheap packaging," of groceries, etc., is from 1977.
generosity (n.): early 15c., "nobility, goodness of race," from Latin generositatem (nominative generositas) "nobility, excellence, magnanimity," from generosus (see generous). Meaning "munificence" is recorded from 1670s.
generous (adj.): 1580s, "of noble birth," from Middle French généreux, from Latin generosus "of noble birth," figuratively "magnanimous, generous," from genus (genitive generis) "race, stock" (see genus). Secondary senses of "unselfish" (1690s) and "plentiful" (1610s) were present in French and in Latin. Related: Generously; generousness.
genesis (n.): Old English Genesis, first book of the Pentateuch, from Latin genesis, adopted as title of first book of Old Testament in Vulgate, from Greek genesis "origin, creation, generation," from gignesthai "to be born," related to genos "race, birth, descent" (see genus). As such, it translated Hebrew bereshith, literally "in the beginning," which was the first word of the text, taken as its title. Extended sense of "origin, creation" first recorded in English c.1600.
genet (n.): small civet, late 15c., from Old French genete (Modern French genette), from Spanish gineta, from Arabic jarnait.
genetic (adj.): "pertaining to origins," coined 1831 by Carlyle from Greek genetikos "genitive," from genesis "origin" (see genus). Biological sense first recorded in Darwin, 1859. Related: Genetically. Genetical is attested from 1650s.
geneticist (adj.): 1913, from genetic + -ist.
genetics (n.): 1872, "laws of origination;" see genetic + -ics. A coinage of English biologist William Bateson (1861-1926). Meaning "study of heredity" is from 1891.
Geneva: city in Switzerland, from Latin Genava, perhaps from a PIE root meaning "estuary" or one meaning "bend;" in either case a reference to its situation. The city was the headquarters of the League of Nations from 1920. The original Geneva Convention to introduce humanitarian conduct in modern warfare dates from 1864; the most recent update was in 1949. The Geneva Protocol is a League of Nations document meant to settle international disputes; it dates from 1924. Earlier the city was associated with Calvinism. Meaning "gin" is from 1706 (see gin (n.1)).
Genevieve: fem. proper name, from French Geneviève, from Late Latin Genovefa, probably of Celtic origin.
genial (adj.): 1560s, "pertaining to marriage," from Latin genialis "pleasant, festive," literally "pertaining to marriage rites," from genius "guardian spirit" (see genius). Originally used in the Latin literal sense; meaning "cheerful, friendly" first recorded 1746. Related: Genially.
geniality (n.): c.1600, "festivity;" 1650s, "cheerfulness," from Late Latin genialitas "festivity, pleasantness," from Latin genialis (see genial).
geniculate (adj.): "having knots or joints," 1660s, from Latin geniculatus, from geniculum "little knee, knot on the stalk of a plant," diminutive of genu "knee" (see knee).
genie (n.): 1650s, "tutelary spirit," from French génie, from Latin genius (see genius); used in French translation of "Arabian Nights" to render Arabic jinni, singular of jinn, which it accidentally resembled, and attested in English with this sense from 1748.
genii (n.): Latinate plural of genius.
genital (adj.): late 14c., in membres genytal "the genitals," from Latin genitalis "pertaining to generation or birth" (also a by-name of the goddess Diana), from genitus, past participle of gignere "to beget" (see genus). As a noun meaning "sex organ" from mid-15c.
genitalia (n.): 1876, Modern Latin, from Latin genitalia (membra), neuter plural of genitalis (see genital).
genitals (n.): "reproductive organs," late 14c., from genital (adj.).
genitival (adj.): 1818, from genitive + -al (1). Related: Genitivally.
genitive (adj.): late 14c., from Old French genitif or directly from Latin (casus) genitivus "case expressing possession, source, origin," from genitus (past participle of gignere; see genital); misused by Latin grammarians to render Greek genike (ptosis) "generic (case)," expressing race or kind (see genus). The noun meaning "the genitive case in grammar" is from 1610s.
genius (n.): late 14c., "tutelary god (classical or pagan)," from Latin genius "guardian deity or spirit which watches over each person from birth; spirit, incarnation, wit, talent;" also "prophetic skill," originally "generative power," from root of gignere "beget, produce" (see kin), from PIE root *gen- "produce." Sense of "characteristic disposition" is from 1580s. Meaning "person of natural intelligence or talent" and that of "natural ability" are first recorded 1640s.
Genoa: city in Italy, Italian Genova, from Latin Genua, perhaps from a PIE root meaning "curve, bend," which means it could be a cognate of Geneva. Other theories hold it to be perhaps from janua "gate," or in reference to the Italic god Janus. Adjective forms in English included Middle English Genoway (also in plural, Janeways), c.1400, from Old French Genoveis, from Italian Genovese. In later English, Genoese is from 1550s; Genovese from c.1600.
genocidal (adj.): 1948, from genocide + -al (1). Related: Genocidally.
genocide (n.): 1944, apparently coined by Polish-born U.S. jurist Raphael Lemkin (1900-1959) in his work "Axis Rule in Occupied Europe" [p.19], in reference to Nazi extermination of Jews, literally "killing a tribe," from Greek genos "race, kind" (see genus) + -cide. The proper formation would be *genticide.
Generally speaking, genocide does not necessarily mean the immediate destruction of a nation, except when accomplished by mass killings of all members of a nation. It is intended rather to signify a coordinated plan of different actions aimed at the destruction of essential foundations of the life of national groups, with the aim of annihilating the groups themselves. [Lemkin]
Earlier in a similar sense was populicide (1799), from French populicide, by 1792, a word from the Revolution. This was taken into German, e.g. Völkermeuchelnden "genocidal" (Heine), which was Englished 1893 as folk-murdering.
genome (n.): "sum total of genes in a set," 1930, modeled on German genom, coined 1920 by German botanist Hans Winkler, from gen "gene" + (chromos)om "chromosome."
genotype (n.): "genetic constitution of an individual," 1910, from German Genotypus (Wilhelm Johannsen, 1909); see gene + type. Earlier the same word was used with a sense of "type species of a genus" (1897); in this case, the first element is from genus.
genre (n.): 1770, as a French word in English (nativized from c.1840), from French genre "kind, sort, style" (see gender). Used especially in French for "independent style." Of painting, "depicting scenes of ordinary life" (as compared to "landscape," "historical," etc.) from 1849.
Genro: "elder statesman of Japan," 1876, from Japanese, literally "first elders."
gens (n.): 1847, in reference to ancient Rome, "tribe, clan, house (of families having a name and certain religious rites in common and a presumed common origin)," from Latin gens (genitive gentis) "race, clan, nation" (see genus).
gent (n.): short for gentleman, by 17c. (in early uses it is difficult to distinguish the shortening from the common abbreviation gent.). "Early in the nineteenth century the word was colloquial and slightly jocular; about 1840 its use came to be regarded as a mark of low breeding" [OED].
genteel (adj.): 1590s, from Middle French gentil "stylish, fashionable, elegant; nice, graceful, pleasing," from Old French gentil "high-born, noble" (11c.); a reborrowing of the French word that had early come into English as gentle (q.v.), with French pronunciation and stress preserved to emphasize the distinction. Cf. also jaunty; gentile. OED 2nd ed. reports genteel "is now used, except by the ignorant, only in mockery" (a development it dates from the 1840s).
gentian (n.): late 14c., genciane, from Old French genciane and directly from Latin gentiana, said by Pliny to be named for Gentius, king of ancient Illyria who discovered its properties. This likely is a folk-etymology, but the word may be Illyrian nonetheless, because the suffix -an frequently occurs in Illyrian words.
gentile (adj.): mid-13c., "noble, kind, gracious" (mid-12c. as a surname); late 14c., "of noble rank or birth, belonging to the gentry," from Late Latin gentilis "foreign, heathen, pagan," from Latin gentilis "person belonging to the same family, fellow countryman," from gentilis (adj.) "of the same family or clan," from gens (genitive gentis) "race, clan" (see gentle).
gentile (n.): late 14c., "chivalrous person; member of the nobility;" see gentile (adj.). Also used during 14c. to mean both "one who is not a Christian" and "one who is not a Jew." The Latin word was used in Vulgate to translate Greek ethnikos, from ta ethne "the nations," which translated Hebrew ha goyim "the (non-Jewish) nations."
gentility (n.): mid-14c., "gentle birth," from Old French gentilité (14c.) or directly from Latin gentilitatem (nominative gentilitas) "relationship in the same family or clan," from gentilis (see gentle). Meaning "state of being gentile" is from 1520s.
gentle (adj.): early 13c., "well-born," from Old French gentil "high-born, noble, of good family" (11c., in Modern French "nice, graceful, pleasing; fine pretty"), from Latin gentilis "of the same family or clan," from gens (genitive gentis) "race, clan," from root of gignere "beget," from PIE root *gen- "produce" (see genus). Sense of "gracious, kind" (now obsolete) first recorded late 13c.; that of "mild, tender" is 1550s. Older sense remains in gentleman.
gentleman (n.): "well-born man," early 13c., from gentle + man.
The Gentleman is always truthful and sincere; will not agree for the sake of complaisance or out of weakness ; will not pass over that of which he disapproves. He has a clear soul, and a fearless, straightforward tongue. On the other hand he is not blunt and rude. His truth is courteous; his courtesy, truthful; never a humbug, yet, where he truthfully can, he prefers to say pleasant things. [J.R. Vernon, "Contemporary Review," 1869]
Related: Gentlemen. Gentleman's agreement is first attested 1929. Gentleman farmer recorded from 1749.
gentlemanly (adj.): mid-15c., from gentleman + -ly (1).