1530s, "guilty of murder;" 1590s, "pertaining to or involved in murder," a hybrid from murder + -ous. An Old English word for it was morðorhycgende. Related: Murderously; murderousness.
Entries linking to murderous
murder n.
"unlawful killing of another human being by a person of sound mind with premeditated malice," c. 1300, murdre, earlier morþer, from Old English morðor (plural morþras) "secret killing of a person, unlawful killing," also "mortal sin, crime; punishment, torment, misery," from Proto-Germanic *murthran (source also of Goth maurþr, and, from a variant form of the same root, Old Saxon morth, Old Frisian morth, Old Norse morð, Middle Dutch moort, Dutch moord, German Mord "murder"), from suffixed form of PIE root *mer- "to rub away, harm" (also "to die" and forming words referring to death and to beings subject to death).
The spelling with -d- probably reflects influence of Anglo-French murdre, from Old French mordre, from Medieval Latin murdrum, which is from the Germanic word. A parallel form murther persisted into 19c.
In Old Norse, custom distinguished morð "secret slaughter" from vig "slaying." The former involved concealment, or slaying a man by night or when asleep, and was a heinous crime. The latter was not a disgrace, if the killer acknowledged his deed, but he was subject to vengeance or demand for compensation.
Mordre wol out that se we day by day. [Chaucer, "Nun's Priest's Tale," c. 1386]
Weakened sense of "very unpleasant situation" is from 1878. Inverted slang sense of "something excellent or terrific" is by 1940. As the name of a parlor or children's game, by 1933.
-ous
word-forming element making adjectives from nouns, meaning "having, full of, having to do with, doing, inclined to," from Old French -ous, -eux, from Latin -osus (compare -ose (1)). In chemistry, "having a lower valence than forms expressed in -ic."