constellation (n.) Look up constellation at
early 14c., constellacioun, "position of a planet in the zodiac;" late 14c., "one of the recognized star patterns handed down from antiquity" (in the zodiac or not), from Old French constellacion "constellation, conjuncture (of planets)," from Late Latin constellationem (nominative constellatio) "set with stars," from constellatus, from Latin com- "with" (see com-) + past participle of stellare "to shine," from stella "star" (see star).

The oldest sense is astrological, of the position of planets ("stars") relative to the constellations on a given day, usually the day of one's birth, as a determiner of one's character. "I folwed ay myn inclinacioun/By vertu of my constillacioun" (Chaucer, "Wife's Prologue," c. 1386).