英语词源字典 - 在线词源网站

lastly (adv.)[lastly 词源字典]: late 14c., from last (adj.) + -ly (2).[lastly etymology, lastly origin, 英语词源]
latch (v.): Old English læccan "to grasp or seize," from Proto-Germanic *lakkijanan. Not found in other Germanic languages; probably from PIE *(s)lagw- "to seize" (see analemma). In its original sense the verb was paralleled in Middle English and then replaced by French import catch (v.). Meaning "to fasten with a latch" is mid-15c. Related: Latched; latching.
latch (n.): a fastening for a door, etc., late 13c., probably from latch (v.).
latchkey: also latch-key, 1825, a key to draw back the latch of a door, from latch (n.) + key (n.1). Latchkey child first recorded 1944, American English, in reference to children who come home from school while both parents are at work.
late (adj.): Old English læt "occurring after the customary or expected time," originally "slow, sluggish," from Proto-Germanic *lata- (cognates: Old Norse latr "sluggish, lazy," Middle Dutch, Old Saxon lat, German laß "idle, weary," Gothic lats "weary, sluggish, lazy," latjan "to hinder"), from PIE *led- "slow, weary" (cognates: Latin lassus "faint, weary, languid, exhausted," Greek ledein "to be weary"), from root *le- "to let go, slacken" (see let (v.)).

The sense of "deceased" (as in the late Mrs. Smith) is from late 15c., from an adverbial sense of "recently." Of women's menstrual periods, attested colloquially from 1962. Related: Lateness. As an adverb, from Old English late.
lateen: mid-18c., phonetic spelling of French latine in voile latine, literally "Latin sail" (see Latin). So called because it was used in the Mediterranean.
lately (adv.): Old English lætlice "slow, sluggish;" see late (adj.) + -ly (2). Meaning "within recent times" is from late 15c., probably a new formation.
latency (n.): 1630s, "condition of being concealed," from latent + -cy. Meaning "delay between stimulus and response" is from 1882; computer sense (latency time) is from 1954.
latent (adj.): mid-15c., "concealed, secret," from Latin latentem (nominative latens) "lying hid, secret, unknown," present participle of latere "to lie hidden," from PIE *laidh-, from root *la- "to be hidden" (cognates: Greek lethe "forgetfulness, oblivion," Old Church Slavonic lajati "to lie in wait for"). Meaning "dormant" is from 1680s.
later: comparative of late. Meaning "farewell" is from 1954, U.S. slang, short for see you later.
lateral (adj.): early 15c., from Middle French latéral and directly from Latin lateralis "belonging to the side," from latus (genitive lateris) "side" (see oblate (n.)). As a noun, from 1630s, "a side part." As a type of pass to the side in U.S. football, it is attested from 1934. Related: Laterally.
Lateran: c. 1300, popular name of cathedral church of St. John Lateran at Rome, which is built on the site of the palace of the Plautii Laterani, a Roman family. As a papal headquarters, it was the site of five general councils of the Western Church.
latescent (adj.): "tending to become latent," 1836, from Latin latescentem (nominative latescens), present participle of latescere "to hide oneself, be hidden," inchoative of latere (see latent).
latest (adj.): superlative of late. The latest "the news" attested from 1886.
latex (n.): 1660s, "body fluid," from Latin latex (genitive laticis) "liquid, fluid," probably from Greek latax "dregs," from PIE root *lat- "wet" (cognates: Middle Irish laith "beer," Welsh llaid "mud, mire," Lithuanian latakas "pool, puddle," Old Norse leþja "filth"). Used 1835 to mean "milky liquid from plants." Meaning "water-dispersed polymer particles" (used in rubber goods, paints, etc.) is from 1937. As an adjective by 1954, in place of clasically correct laticiferous.
lath (n.): late 13c., probably from Old English *læððe, variant of lætt "lath," apparently from a Proto-Germanic *laþþo (cognates: Old Saxon, Old Norse latta, Middle Dutch, German latte "lath," Dutch lat, Middle High German lade "plank," which is source of German Laden "counter," hence, "shop"). As a verb, 1530s, from the noun.
lathe (n.): "machine for turning," early 14c., of uncertain origin, probably from a Scandinavian source (compare Danish drejelad "turning-lathe," Old Norse hlaða "pile of shavings under a lathe," related to hlaða "to load, lade;" see lade (v.)).
lather (n.): Old English lauþr "foam, washing soda," from Proto-Germanic *lauthran (cognates: Old Norse lauðr "washing soap, foam"), from PIE *loutro- (cognates: Gaulish lautron, Old Irish loathar "bathing tub," Greek louein "to bathe," Latin lavere "to wash"), which is from root *leu(e)- "to wash" + instrumentative suffix *-tro-. The modern noun might be a 16c. redevelopment from the verb. Meaning "violent perspiration" (especially of horses) is from 1650s. Meaning "state of agitation" (such as induces sweating) is from 1839.
lather (v.): Old English laþran, from Proto-Germanic *lauthrjan (source also of Old Norse leyðra "to clean, wash;" see lather (n.)). Related: Lathered; lathering.
Latin (adj.): Old English latin, from Latin Latinus "belonging to Latium," the region of Italy around Rome, possibly from PIE root *stela- "to spread, extend," with a sense of "flat country" (as opposed to the mountainous district of the Sabines), or from a prehistoric non-IE language. The Latin adjective also was used of the Roman language and people.
Centurion: What's this, then? "People called Romanes they go the house?"
Brian: It ... it says, "Romans, go home."
Centurion [thrashing him like a schoolboy]: No, it doesn't. 'Go home?' This is motion towards. Isn't it, boy?
Brian: Ah ... ah, dative, sir! Ahh! No, not dative! Not the dative, sir! No! Ah! Oh, the ... accusative! Domum, sir! Ah! Oooh! Ah!
Centurion [pulling him by the ear]: Except that domum takes the ...?
Brian: The locative, sir!
[Monty Python, "Life of Brian"]
Used as a designation for "people whose languages descend from Latin" (1856), hence Latin America (1862). The Latin Quarter (French Quartier latin) of Paris, on the south (left) bank of the Seine, was the site of university buildings in the Middle Ages, hence the place where Latin was spoken. The surname Latimer, Lattimore, etc. is from Vulgar Latin latimarus, from Latin latinarius "interpreter," literally "a speaker of Latin." "What Latin was to the learned, that their tongue was to laymen; hence latino was used for any dialect, even Arabic and the language of birds ...." [Donkin, "Etymological Dictionary of the Romance Languages," 1864].