The rare adjective riant is a direct borrowing from the French present participle riant “laughing,” from the verb rire, ultimately from Latin rīdēre “to laugh,” which comes from a very complicated Proto-Indo-European root wer- “to twist, bend” (rīdēre would mean “twist the face or mouth”). Wer- has many suffixes and extensions that form some startling words. The meaning of the root extended with the suffix -t is clearly seen in Latin vertere “to turn,” with its many English derivatives, e.g., revert, convert, invert. The Germanic form of wert- is werth-, source of the English suffix -ward(s), as in homeward(s), toward(s). A variant form of wer- with the suffix -m forms Latin vermis “worm” (from its twisting) and Germanic wurmiz (Old English wyrm “dragon, serpent”; English worm). Finally, somewhat related to rīdēre is the Latin noun rictus “wide open mouth, gaping jaws” (English rictus). Riant entered English in the 16th century.
Mistress Marjory bent her head with a murmured assurance of “giving him small trouble,” but again the riant eyes belied the lips …
At the head of that open and legal agitation, was a man of giant proportions in body and mind; … a humor broad, bacchant, riant, genial and jovial …
adjective
oriented or coiled in a leftward direction, as a left-spiraling snail shell.
The adjective laeotropic “turning leftward” is restricted to describing snail shells. The second element, -tropic “turning (to),” is common enough in the physical sciences, e.g., geography, meteorology, chemistry. The first element laeo- is rare. It comes from the Greek adjective laiós “left, on the left” (there is one ancient lexicographical reference implying the form laiwós). Laiwós is all but identical to Latin laevus and pretty close to Slavic (Polish) lewy. Outside these three branches of the Indo-European languages (and possibly also Lithuanian, among the Baltic languages), laiwo- does not occur. Laeotropic entered English in the 19th century.
The arms of the cross are slightly oblique; and it is worthy of note that the direction of their inclination is laeotropic, while in Crepidula and Ischnochiton the arms show a slight dexiotropic twist.
… the direction of corresponding cleavages is the same, i.e., the second cleavage is laeotropic and the third dexiotropic, and so on …. Why should this constancy occur?
noun
Astronomy. any of a shower of meteors appearing in August and radiating from a point in the constellation Perseus.
Perseid may have been introduced into English from Italian Perseidi, coined by the distinguished Italian astronomer Giovanni Schiaparelli (1835-1910), who is unfortunately best remembered today for the mistranslation into English of Italian canali “channels” on Mars as “canals,” which has inspired decades and decades of science fiction. Perseid ultimately comes from Greek Perseídēs “offspring or daughters of Perseus,” because the meteors appear to be coming from the constellation Perseus. Perseid entered English in the 19th century.
Comet Swift-Tuttle is the largest object known to repeatedly pass by Earth; its nucleus is about 16 miles (26 kilometers) wide. It last passed nearby Earth during its orbit around the sun in 1992, and the next time will be in 2126. But it won’t be forgotten in the meantime, because Earth passes through the dust and debris it leaves behind every year, creating the annual Perseid meteor shower.
The Perseids also feature “fireballs,” which are meteors of bright color and longer streaks that sometimes have “magnitudes greater than -3.”