umbra versaとは 意味・読み方・使い方

語源

First attested in Modern English in 1688, although the phrase was also used in Middle English by Geoffrey Chaucer (c. 1343–1400) in his Treatise on the Astrolabe; Latin: umbra (“shadow”) + versa (feminine nominative 単数形 of versus, “turned”) = “turned shadow”; compare umbra recta.

発音

• (Received 発音) enPR: ŭmʹbrə vûrʹsə, IPA^(key): /ˈʌmbɹə ˈvɜːsə/

名詞

umbra versa

1. On a shadow in the shape of a right triangle, the length of the shadow's edge opposite to a measured angle.
   • 1688, John Hales, “The Rich man’s Recepiſti” in Golden Remains (3rd ed.), page 77

     Scheubelius a great Mathematician, but by book only, and not by practice who being required ſometime in an Army to make uſe of his Quadrant, knew not the difference between umbra recta, and umbra verſa.

同意語

• umbra stans