1828, from Fr. morphine or Ger. Morphin (1816),
name coined in allusion to L. Morpheus, Ovid's name for the god of dreams, son of Sleep, lit. "the maker of shapes,"
from Gk. morphe "form, shape, beauty, outward appearance,"
perhaps from PIE *merph-, possible Gk. root meaning "form," of unknown origin.
So called because of the drug's sleep-inducing properties.