variety of banded, colored quartz, 1560s, from French agate, from Latin achates, from Greek akhatēs, the name of a river in Sicily where the stones were found (Pliny). But the river could as easily be named for the stone.

Earlier in English as achate (early 13c.), directly from Latin. The Elizabethan sense of "a diminutive person" is from the small figures cut in agates for seals, etc., and the notion of smallness is preserved in typographer's agate (1838), the U.S. name of the 5.5-point font called in Great Britain ruby. Meaning "toy marble made of glass resembling agate" is from 1843 (colloquially called an aggie). Related: Agatine.

late 14c., "a large mass;" mid-15c., "spherical solid body, a sphere," from Old French globe (14c.) and directly from Latin globus "round mass, sphere, ball" (also, of men, "a throng, crowd, body, mass"), which is related to gleba "clod, lump of soil" (see glebe) and perhaps also to glomus "a ball, ball of yarn."

Sense of "the planet earth," also "map of the earth or sky drawn on the surface of an artificial sphere" are attested from 1550s. Meaning "globe-shaped glass vessel" is from 1660s. "A globe is often solid, a sphere often hollow. The secondary senses of globe are physical; those of sphere are moral." [Century Dictionary].

Old English cnotta "intertwining of ropes, cords, etc.," from Proto-Germanic *knuttan- (source also of Low German knütte, Old Frisian knotta "knot," Dutch knot, Old High German knoto, German Knoten, perhaps also Old Norse knutr "knot, knob"). For pronunciation, see kn-.

Figurative sense of "difficult problem, a perplexity" was in Old English (compare Gordian knot). Symbolic of the bond of wedlock from early 13c. As an ornament of dress, first attested c. 1400. Meaning "thickened part or protuberance on tissue of a plant" is from late 14c. As "small group or cluster of persons" late 14c.

The nautical unit of measure of speed (1630s) is from the practice of attaching knotted string to the log line at equal distances (see log (n.2)). The ship's speed can be measured by the number of knots that play out while the sand glass is running.

The distance between the knots on the log-line should contain 1/120 of a mile, supposing the glass to run exactly half a minute. [Jorge Juan and Antonio de Ulloa, "A Voyage to South America" 1760]

Hence the word knot came also to be used as the equivalent of a nautical mile (in pre-World War II use in U.S. and Britain, about 6,080 feet). A speed of 10 knots will cover ten nautical miles in an hour (equivalent to a land speed of about 11.5 mph).

1830, "artificial pond in a garden or elsewhere for growing aquatic plants," noun use of neuter of Latin aquarius "pertaining to water" (also, as a noun, "water-carrier"), genitive of aqua "water" (from PIE root *akwa- "water").

The noun aquarium in Latin meant "drinking place for cattle." In English, the meaning "vessel of glass filled with water in which living aquatic animals are kept indoors" is by 1853. The Victorian mania for indoor aquariums began with the book "The Aquarium," published 1854 by English naturalist Philip Henry Gosse. An earlier attempt at a name for "fish tank" was marine vivarium.

Middle English anelen, from Old English onælan "to set on fire, kindle; inspire, incite," from on- "on" (see an- (1)) + ælan "to burn, bake," from Proto-Germanic *ailan, "probably" [Watkins] from the same PIE root meaning "to burn" that is the source of ash (n.1). It is related to Old English æled "fire, firebrand," Old Norse eldr, Danish ild "fire."

The -n- was doubled after c. 1600 by analogy of Latinate words (annex, etc.; compare accursed, afford, allay). Meaning "to treat by heating and gradually cooling" (of glass, earthenware, metals, etc., to toughen them) was in late Old English. Related: Annealed; annealing.

1560s, in geometry, "a solid whose bases or ends are any similar, equal, and parallel plane polygons, and whose sides are parallelograms" (not always triangular), from Late Latin prisma, from Greek prisma "a geometrical prism, trilateral column," (Euclid), literally "something sawed (as a block of wood), sawdust," from prizein, priein "to saw" (related to prion "a saw"), which is of uncertain origin. Euclid chose the word, apparently, on the image of a column with the sides sawn off.

Specific sense in optics, "an instrument (usually triangular) with well-polished sides of glass, quartz, etc., which refracts light and spreads it in a spectrum," is attested from 1610s.

children's game, from plural of marble (n.); the game is recorded by that name by 1709 but is probably older (it was known in 13c. German as tribekugeln). It originally was played with small balls of polished marble or alabaster, later of clay. Glass marbles with the colored swirl date from the 1840s.

Meaning "mental faculties, common sense" (as in to lose or not have all one's marbles) is by 1927, American English slang, perhaps [OED] from earlier slang marbles "furniture, personal effects, 'the goods' " (1864, Hotten), a corrupt translation of French meubles (plural) "furniture" (see furniture).

formerly also cristal, and, erroneously, chrystal, Old English cristal "clear ice; clear, transparent mineral," from Old French cristal (12c., Modern French crystal), from Latin crystallus "crystal, ice," from Greek krystallos, from kryos "frost," from PIE root *kreus- "to begin to freeze, form a crust."

The spelling adopted the Latin form 15c.-17c. The mineral has been so-called since Anglo-Saxon times; it was regarded by the ancients as a sort of petrified ice. In the specific sense in chemistry, "body with a molecular structure that causes it to take the form of a regular solid enclosed by a certain number of plane surfaces," from 1620s.

Crystall is a brighte stone and clere with watry colour. Men trowe that it is of snowe or yse made harde in space of many yeres. Therfore the Grekes yave a name therto. It is gendred in Asia and in Cipres, and namely in the northe moutaynes where the sonne is mooste feruent in somer. [Bartholomew Glanville, "De proprietatibus rerum," c. 1240, translated by John of Trevisa c. 1398]

A top-20 name for girls born in the U.S. between 1978 and 1984. As a shortened form of crystal-glass it dates from 1590s. As an adjective, from late 14c. Crystal ball is from 1794.  Rock-crystal is the general name for transparent crystals of quartz. Crystal Palace was the name of the large building, made chiefly of glass and iron, for the universal exhibition of 1851 in London's Hyde Park.

1708, "vaulted building; arched roof or ceiling," from Latin camera "a vault, vaulted room" (source also of Italian camera, Spanish camara, French chambre), from Greek kamara "vaulted chamber, anything with an arched cover," which is of uncertain origin. A doublet of chamber. Old Church Slavonic komora, Lithuanian kamara, Old Irish camra all are borrowings from Latin.

The word also was used from early 18c. as a short form of Modern Latin camera obscura "dark chamber" (a black box with a lens that could project images of external objects), contrasted with camera lucida (c. 1750, Latin for "light chamber"), which uses prisms to produce an image of a distant object on paper beneath the instrument which can be traced.

This sense was expanded to become the word for "picture-taking device used by photographers" (the thing a modification of the camera obscura) when modern photography began c. 1840. The word was extended to television filming devices from 1928. Camera-shy is attested from 1890. Camera-man is from 1908.

mid-13c., "garment, cloak, mantle; a part of a garment;" later "side of a building, section of a wall," from Old French pan "section, piece, panel" (11c.) and directly from Latin pannum (nominative pannus) "piece of cloth, garment," possibly from PIE root *pan- "fabric" (source also of Gothic fana "piece of cloth," Greek pēnos "web," Old English fanna "flag"). De Vaan writes, "If the Gr. and Gm. words listed are related, they probably represent loanwords from an unknown source."

From late 14c. as "section of a wall," also "ornamental hanging, coverlet," and c. 1400 as "a bedspread." The general notion in the word is "distinct part or piece of a surface." Sense of "piece of glass inserted in a window" is attested by mid-15c.