An Etymological Dictionary of Astronomy and Astrophysics

The Serpent. An inconspicuous, irregular constellation situated on both sides of → Ophiuchus. The constellation is divided into two unequal parts, originally called Serpens Caput “Serpent’s Head” at 15h 30m right ascension, 15° north declination, and Serpens Cauda “Serpent’s Body” at 18h 30m right ascension, 0° declination. The brightest star, Alpha Serpentis, is of second magnitude.
Abbreviation: Ser; Genitive: Serpentis.

Etymology (EN): From L. serpens “snake,” from pr.p. of serpere “to creep,” from PIE *serp- “to crawl;” cf. Skt. sarp- “to creep, crawl,” sárpati “creeps,” sarpá- “serpent;” Gk. herpein “to creep,” herpeton “serpent;” Alb. garper “serpent.”

Etymology (PE): Mâr “snake, serpent;” Mid.Pers. mâr “snake;” Av. mairya- “snake, serpent.”