angel (n.)youdaoicibaDictYouDict
14c. fusion of Old English engel (with hard -g-) and Old French angele, both from Latin angelus, from Greek angelos "messenger, envoy, one that announces," possibly related to angaros "mounted courier," both from an unknown Oriental word (Watkins compares Sanskrit ajira- "swift;" Klein suggests Semitic sources). Used in Scriptural translations for Hebrew mal'akh (yehowah) "messenger (of Jehovah)," from base l-'-k "to send." An Old English word for it was aerendgast, literally "errand-spirit."

Of persons, "loving; lovely," by 1590s. The medieval gold coin (a new issue of the noble, first struck 1465 by Edward VI) was so called for the image of archangel Michael slaying the dragon, which was stamped on it. It was the coin given to patients who had been "touched" for the King's Evil. Angel food cake is from 1881; angel dust "phencyclidine" is from 1968.
mislay (v.)youdaoicibaDictYouDict
c. 1400, from mis- (1) + lay (v.). Related: Mislaid; mislaying.
murder (n.)youdaoicibaDictYouDict
c. 1300, murdre, from Old English morðor (plural morþras) "secret killing of a person, unlawful killing," also "mortal sin, crime; punishment, torment, misery," from Proto-Germanic *murthra- (cognates: 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 PIE *mrtro-, from root *mer- "to die" (see mortal (adj.)). The spelling with -d- probably reflects influence of Anglo-French murdre, from Old French mordre, from Medieval Latin murdrum, from the Germanic root.

Viking custom, typical of Germanic, distinguished morð (Old Norse) "secret slaughter," from vig (Old Norse) "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.