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Origin and history of radioactive

radioactive(adj.)

1898, of an atomic nucleus, "capable of spontaneous nuclear decay releasing ionizing emissions," from French radio-actif, coined by Pierre and Marie Curie from radio-, combining form of Latin radius "ray" (see radius) + actif "active" (see active). Of processes, etc., "involving or produced by radioactivity," by 1903.

also from 1898

Entries linking to radioactive

active(adj.)

mid-14c., actif, active, "given to worldly activity" (opposed to contemplative or monastic), from Old French actif (12c.) and directly from Latin activus, from actus "a doing" (from PIE root *ag- "to drive, draw out or forth, move").

As "capable of acting" (opposed to passive), from late 14c. Meaning "energetic, lively" is from 1590s; that of "working, effective, in operation" (opposed to inactive) is from 1640s. The grammatical active voice is recorded from 1765; grammatical use of active, signifying performance and not endurance of an action, dates from mid-15c. (opposed to passive or reflexive).

radius(n.)

1590s, "cross-shaft, straight rod or bar," from Latin radius "staff, stake, rod; spoke of a wheel; ray of light, beam of light; radius of a circle," a word of unknown origin. Perhaps related to radix "root," but de Vaan finds that "unlikely." The classical plural is radii. 

The geometric sense of "straight line drawn from the center of a circle to the circumference" is recorded from 1650s. Meaning "circular area of defined distance around some place" is attested from 1853. As the name of the shorter of the two bones of the forearm from 1610s in English (the Latin word had been used thus by the Romans).

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carbon
Carbon 14, the long-lived radioactive isotope used in dating organic deposits, is from 1936....
box
"rectangular wooden container," usually with a lid, Old English box, also the name of a type of shrub, from Late Latin buxis, from Greek pyxis "boxwood," pyxion "writing table, box," made of boxwood, from pyxos "box tree," which is of uncertain origin. Beekes suggests a loan-word
curry
late 13c., "to rub down a horse," from Anglo-French curreier "to curry-comb a horse," from Old French correier "put in order, prepare, curry," from con-, intensive prefix (see com-), + reier "arrange," from a Germanic source (see ready). Related: Curried; currying. To curry favor
pomp
c. 1300, "ostentation and display," especially on parade, from Old French pompe "pomp, magnificence" (13c.) and directly from Latin pompa "procession, pomp," from Greek pompē "solemn procession, display, escort," literally "a sending," from pempein "to send," which is of unknown
James
masc. proper name, New Testament name of two of Christ's disciples, late 12c. Middle English vernacular form of Late Latin Jacomus (source of Old French James, Spanish Jaime, Italian Giacomo), altered from Latin Jacobus (see Jacob). The Welsh form was Iago, the Cornish Jago. Jame
mitigate
early 15c., "relieve (pain); make mild or more tolerable; reduce in amount or degree," from Latin mitigatus, past participle of mitigare "soften, make tender, ripen, mellow, tame," figuratively, "make mild or gentle, pacify, soothe," ultimately from mitis "gentle, soft" + root of
trivial
"ordinary" (1580s); "insignificant, trifling" (1590s), from Latin trivialis "common, commonplace, vulgar," literally "of or belonging to the crossroads," from trivium "place where three roads meet," in transferred use, "an open place, a public place," from tri- "three" (see three
education
1530s, "child-rearing," also "the training of animals," from French education (14c.) and directly from Latin educationem (nominative educatio) "a rearing, training," noun of action from past-participle stem of educare (see educate). Originally of instruction in social codes and m

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