Definition of "murky"

The Streets of London, to be beheld in the very height of their glory, should be seen on a dark, dull, murky, winter's night, when there is just enough damp gently stealing down to make the pavement greasy without cleansing it of any of its impurities, […]

1837, “Boz” [pseudonym; Charles Dickens], “The Streets by Night”, in Sketches by Boz: Illustrative of Every-day Life, and Every-day People. The Second Series, London: John Macrone, […], page 19

Ferdinand: As I hope / For quite dayes, faire Iſſue, and long life, / With ſuch loue, as 'tis now the murkieſt den, / The moſt opportune place, the ſtrongſt ſuggeſtion, / Our worſer Genius can, shall neuer melt / Mine honor into luſt, […]

1610–1611 (date written), William Shakespeare, “The Tempest”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act IV, scene i], page 14

They may face an impenetrable word, approach its murky history from every direction, and fail to find a convincing solution (or even any solution: “origin unknow,” “the rest is unclear,” and the like).

2021 April 21, Anatoly Liberman, “Going out on a Limb”, in Oxford Etymologist‎

Mr. Farrier, 39, said he often questioned the moral implications of his trips. “It’s very ethically murky territory,” Mr. Farrier said.

2022 October 28, Maria Cramer, “Beaches? Cruises? ‘Dark’ Tourists Prefer the Gloomy and Macabre”, in The New York Times‎

China’s murky statistics are fueling widespread public distrust. Its narrow definition of Covid deaths “will very much underestimate the true death toll,” the W.H.O. says.

2022 December 23, Keith Bradsher, Amy Chang Chien, Joy Dong, “As Cases Explode, China’s Low Covid Death Toll Convinces No One”, in The New York Times‎