Definition of "murther"

Murther most foul, as in the best it is; / But this most foul, strange, and unnatural.

c. 1599–1602 (date written), William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act I, scene v]

We have some Inſtances of publick Puniſhment inflicted on ſuch Midwives, in the Neighbouring Kingdom of France, for being acceſſory to the murther both of the Mother and Child.

1699, Robert Barret, A Companion for Midwives, Child-Bearing Women, and Nurses., London, Sect. I, Chapter I, p. 5

In the meane time it chaunced, that Marcus Papyrius ſtroke one of the Galles on the heade with his ſtaffe, because he preſumed to ſtroke his bearde: with whiche iniurie the Gaulle beeing prouoked, ſlue Papyrius (as he ſate) with hys ſworde, and therewith the ſlaughter being begun with one, all the reſidue of thoſe auncient fatherly men as they ſat in theyr Chayres were ſlaine and cruelly murthered.

1577, Raphaell Holinshed, “The Historie of Englande”, in The Firste Volume of the Chronicles of England, Scotlande, and Irelande […], volume I, London: […] [Henry Bynneman] for Iohn Harrison, page 26, columns 1–2

What wilt thou do? Thou wilt not murther me?

c. 1599–1602 (date written), William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene iv]