ancient constellation (representing Aesculapius), 1650s, from Latin, from Greek ophioukhos, literally "holding a serpent," from ophis "serpent" (see ophio-) + stem of ekhein "to hold, have, keep" (from PIE root *segh- "to hold").

Translated in Latin as Anguitenens and Serpentarius. Milton's "Ophiuchus huge in th' Arctick Sky" ("Paradise Lost") is a rare (minor) lapse for a poet who generally knew his astronomy; the constellation actually straddles the celestial equator, and, as its modern boundaries are drawn, dips into the zodiac: The sun passes through Ophiuchus from about Nov. 30 to Dec. 18. The serpent now is treated as a separate constellation.

Others are reading

Definitions of Ophiuchus from WordNet

Ophiuchus (n.)
a large constellation in the equatorial region between Hercules and Scorpius;