Definition of "mirk"

The thickness of mirk is bad enough, but the thickness of white, illimitable ether is worse a thousandfold, for it closes the eye and mazes the wits.

1899, John Buchan, Grey Weather, published 2008, page 4

Outside the chapel in the weeping mirk a squire held his shield, another his helm, a groom walked his horse.

1900, Maurice Hewlett, The Life and Death of Richard Yea-and-Nay, published 2008, page 18

The English cries of the soldiers were answered in English by the Boers, and slouch hat or helmet dimly seen in the mirk was the only badge of friend or foe.

1900, Arthur Conan Doyle, The Great Boer War, published 2010, unnumbered page

She disappeared into the gathering mirk.

2011, Douglas Watt, Testament of a Witch, page 178

And there they lay so near his little heart, / With whispering of things that happened not, / Until the serpent green had mirked / His manly vision in a way that lost / The anchorage of balanced sanity.

1903, J. Vinton Webster, Augusta: A Drama in Four Acts, published 2004, act 4, scene 1, page 121

What gars this din of mirk and baleful harm, / Where everywean is all betaint with bloud?

c. 1590, Robert Greene, The Scottish History of James the Fourth, Act 5, Chorus 6, Norman Sanders (editor), 1973, The Revels Plays: James the Fourth, page 128

Chill and mirk is the nightly blast, / Where Pindus' mountains rise, / And angry clouds are pouring fast / The vengeance of the skies.

1809, Lord Byron, “Stanzas Composed During a Thunderstorm”, in The Works of Lord Byron, volume 7, published 1834, page 311

It was by this time the mirkest of the gloaming, for they had purposely tarried on the journey that they might enter Edinburgh at dusk.

1823, John Galt, Ringan Gilhaize: Or, The Covenanters, volume 1, page 95

It's a lang, laigh, mirk chalmer, perishin' cauld in winter, an' no very dry even in the tap o' the simmer, for the manse stands near the burn.

1887, Robert Louis Stevenson, “Thrawn Janet”, in The Merry Men and Other Tales and Fables