Etymology
Advertisement
Almagest (n.)
late 14c., title of a treatise on astronomy by Claudius Ptolemy of Alexandria, from Old French almageste (13c.), from Arabic al majisti, from al "the" + Greek megiste "the greatest (composition)," from fem. of megistos, superlative of megas "great" (from PIE root *meg- "great").

Originally titled in Greek Mathematike syntaxis ("Mathematical Composition"), commonly called Megale syntaxis "Great Composition" (Greek megale is the fem. of megas); Arab translators in their admiration altered this. Extended in Middle English to other works on astrology or astronomy,
Related entries & more 
Advertisement
sunspot (n.)
also sun-spot, 1849, in astronomy, from sun (n.) + spot (n.). Earlier "a spot on the skin caused by exposure to the sun" (1818).
Related entries & more 
quartile (n.)

mid-15c., originally in astrology and astronomy in the phrase quartile aspect in reference to celestial bodies when 90 degrees apart in longitude; see quartile (adj.). In statistics, from 1879.

Related entries & more 
mathematical (adj.)

"of, pertaining to, or of the nature of mathematics," early 15c., from Medieval Latin mathematicus "of or belonging to mathematics," from Latin mathematica (see mathematic) + -al (1). Also, by 1765, "pertaining to the quadrivium," comprising arithmetic, geometry, astronomy, and music. It also could include optics. Related: Mathematically.

The four mathematical arts are arithmetic, geometry, music, and astronomy; these anciently were termed the quadrivium, or fourfold way of knowledge. [Sir John Hawkins, "A General History of the Science and Practice of Music," Sir John Hawkins, 1776]
Related entries & more 
sunglasses (n.)
glasses with darkened lenses to protect one's eyes while observing the sun, also sun-glasses, 1878, from sun (n.) + glasses. In popular (non-astronomy) use from 1916. Earlier sunglass (1804) meant a burning glass.
Related entries & more 
Advertisement
octant (n.)

instrument for making angular measurements in navigation or astronomy, 1731, from Late Latin octans "the eighth part," from octo "eight" (see octa-) on analogy of quadrant. In geometry, "the eighth part of a circle," by 1750.

Related entries & more 
flare (n.)
"a giving off of a bright, unsteady light," 1814, from flare (v.). This led to the sense of "signal fire" (1883). The astronomy sense is from 1937. Meaning "a gradual widening or spreading" is from 1910; hence flares "flared trousers" (1964).
Related entries & more 
radiant (n.)

in optics, "point or object from which light radiates," 1714; see radiant (adj.). In astronomy, of meteor showers, "the point in the heavens from which the shooting stars seem to proceed," by 1834, in reference to the great shower of the previous November.

Related entries & more 
fascia (n.)
1560s, from Latin fascia "a band, bandage, swathe, ribbon," derivative of fascis "bundle" (see fasces). In English, originally in architecture; anatomical use is from 1788. Also used in botany, music, astronomy. Related: Fascial; fasciation.
Related entries & more 
luminosity (n.)
1630s, "quality of being luminous," from French luminosité (cognate with Medieval Latin luminositas "splendor") or else a native formation from luminous + -ity. Meaning "intensity of light in a color" (of a flame, spectrum, etc.) is from 1876. In astronomy, "intrinsic brightness of a heavenly body" (as distinguished from apparent magnitude, which diminishes with distance), attested from 1906.
Related entries & more 

Page 2