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[ sel-uh-nog-ruh-fee ] [ ˌsɛl əˈnɒg rə fi ] Show IPA Phonetic Respelling


the branch of astronomy that deals with the charting of the moon's surface.

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More about selenography

Selenography “the branch of astronomy that charts the moon’s surface” is a compound of seleno- and -graphy. The former comes from Ancient Greek selḗnē “moon,” while the latter ultimately comes from Ancient Greek graphḗ “writing.” The noun selḗnē is also the source of Selene, the moon goddess, and comes from sélas “shine,” plus the noun-forming suffix -nē, making selḗnē literally mean “shinier, lighter.” A similar formation appears in Latin with lūna “moon,” contracted from the root luc- “light” and the suffix -na. Take care not to confuse Selene with the name Celine, from either Latin Caelina (from caelum “heaven”) or French Marceline (from Latin Marcus). Selenography was first recorded in English in the 1640s.

how is selenography used?

In the history of Selenography, John Henry Maedler holds a distinguished place. He was the very first to publish a large map of the lunar surface; and his map was a good one, very accurate, and beautifully executed.

Sabine Baring-Gould, Historic Oddities and Strange Events, 1889

The selenography of one side of the moon is much better known to us than the geography of the earth. Our maps of the moon are far more perfect than those of the earth…

Henry White Warren, Recreations in Astronomy with Directions for Practical Experiments and Telescopic Work, 1879
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[ gal-uhnt-lee ] [ ˈgæl ənt li ] Show IPA Phonetic Respelling


in a courageous, spirited, or noble-minded way.

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More about gallantly

Gallantly “in a courageous way” is a compound of the adjective gallant and the adverb-forming suffix -ly. The -ant element in gallant is a telltale sign of the word’s origin; -ant is a common marker appearing in both French and Latin that shows that a word was originally a present participle. Just as tenant means “holding” in Middle French and radiant comes from Latin radiāns “shining,” gallant was the Old French present participle, meaning “amusing oneself,” of the verb galer “to amuse oneself, make merry.” Because of the sound change from w to g (or gu) when French borrowed Germanic words (usually from Frankish), gallant is a distant relative of English wealth, well, and will. For another example of this w/g contrast, compare the recent Word of the Day guerdon. Gallantly was first recorded in English in the mid-16th century.

how is gallantly used?

Sen. Daniel Inouye, the second-longest serving senator in U.S. history, was remembered Thursday as a man who gallantly defended his country on the battlefield and gracefully sought to better it during the 50-plus years he represented his beloved state of Hawaii.

Kevin Freking, “Final Capitol tribute to late Hawaii Sen. Inouye,” AP News, December 20, 2012

Camoëns lost an eye in the service of his king as gallantly as Cervantes lost a hand at Lepanto. It is an undisputed fact that during the siege of Paris there was scarcely a painter or poet or sculptor or musician who did not enlist in the army and do battle for his country at bitter need …

S. R. Elliott, “The Courage of a Soldier,” The Atlantic, February 1893
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[ had-ron ] [ ˈhæd rɒn ] Show IPA Phonetic Respelling


any elementary particle that is subject to the interaction responsible for the short-range attractive force that holds together the nucleus of the atom.

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More about hadron

Hadron “an elementary particle subject to the strong nuclear force” is a coinage based on Ancient Greek hadrós “thick, bulky” or “strong, great,” with the suffix -on (clipped from ion). Hadron is not related to the name Hadrian, which comes from a Roman place name that is also the source of Adriatic. Some linguists connect hadrós to Old English sæd “sated, full” or “heavy, weary” (compare modern English sad) on the grounds that Ancient Greek h tends to correspond to English s. If this connection is valid, that also makes hadrós a relative of Latin satis “enough” (found in asset, satiate, and satisfy) and satur “full, well-fed” (found in satire and saturate). Russian physicist Lev Okun created hadron in 1962 as a counterpart of lepton (from Ancient Greek leptós “small, slight”).

how is hadron used?

Protons are the only hadrons known to be stable in isolation—neutrons are stable only when they are incorporated into atomic nuclei. All other hadrons form only fleetingly, from the collision of other particles, and decay in a fraction of a second. So the LHC [Large Hadron Collider] creates new kinds of hadron by causing high-energy, head-on collisions between protons.

Davide Castelvecchi, “Exotic Four-Quark Particle Spotted at Large Hadron Collider,” Scientific American, August 11, 2021

Quarks are elementary particles that usually combine in groups of twos and threes to form hadrons such as the protons and neutrons that make up atomic nuclei. More rarely, however, they can also combine into four-quark and five-quark particles, or tetraquarks and pentaquarks.

Michael Shields, “Scientists at CERN observe three 'exotic' particles for first time,” National Post, July 5, 2022
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