murky

Murky, a. [Compar. Murkier; superl. Murkiest.]

Etymology: [OE. mirke, merke, AS. myrce, mirce; akin to Icel. myrkr, Dan. & Sw. mörk.]

Dark; obscure; gloomy. "The murkiest den." Shak. A murky deep lowering o'er our heads. Addison.

Shades of meaning

Fernald has no entry of its own for murky; he lists it under dark.

Where he writes about it:

Murky is said of that which is at once dark, obscure, and gloomy; as, a murky den; a murky sky. — from dark