Darkness

1. 1. Lacking or having very little light: a dark corner.

   2. Lacking brightness: a dark day.

2. Reflecting only a small fraction of incident light.

3. Of a shade tending toward black in comparison with other shades. Used of a color.

4. Having a complexion that is not fair; swarthy.

5. Served without milk or cream: dark coffee.

6. Characterized by gloom; dismal: took a dark view of the consequences.

7. Sullen or threatening: a dark scowl.

8. Difficult to understand; obscure: stories that are large in scope and dark in substance.

9. Concealed or secret; mysterious: "the dark mysteries of Africa and the fabled wonders of the East" (W. Bruce Lincoln).

10. Lacking enlightenment, knowledge, or culture: a dark age in the history of education.

11. Exhibiting or stemming from evil characteristics or forces; sinister: "churned up dark undercurrents of ethnic and religious hostility" (Peter Maas).

12. Being or characterized by morbid or grimly satiric humor.

13. Having richness or depth: a dark, melancholy vocal tone.

14. Not giving performances; closed: The movie theater is dark on Mondays.

15. Linguistics Pronounced with the back of the tongue raised toward the velum. Used of the sound (l) in words like full.

1. Absence of light.

2. A place having little or no light.

3. Night; nightfall: home before dark.

4. A deep hue or color.

Synonyms: These adjectives indicate the absence of light or clarity. Dark, the most widely applicable, can refer to insufficiency of illumination for seeing (a dark evening), deepness of shade or color (dark brown), absence of cheer (a dark, somber mood), or lack of rectitude (a dark past). Dim suggests lack of clarity of outline: "life and the memory of it cramped,/dim, on a piece of Bristol board" (Elizabeth Bishop).
It can also apply to a source of light to indicate insufficiency: "storied Windows richly dight,/Casting a dim religious light" (John Milton).
Murky implies darkness, often extreme, such as that produced by smoke or fog: "The path was altogether indiscernible in the murky darkness which surrounded them" (Sir Walter Scott).
Dusky suggests the dimness that is characteristic of diminishing light, as at twilight: "The dusky night rides down the sky,/And ushers in the morn" (Henry Fielding).
Also, it often refers to deepness of shade of a color: "A dusky blush rose to her cheek" (Edith Wharton).
Obscure usually means unclear to the mind or senses, but it can refer to physical darkness: the obscure rooms of a shuttered mansion.
Opaque means incapable of being penetrated by light: an opaque window shade
; figuratively it applies to something that is unintelligible: opaque philosophical arguments.
Shady refers literally to what is sheltered from light, especially sunlight (a shady grove of pines) or figuratively to what is of questionable honesty (shady business deals). Shadowy also implies obstructed light (a shadowy path) but may suggest shifting illumination and indistinctness: "[He] retreated from the limelight to the shadowy fringe of music history" (Charles Sherman).
It can also refer to something that seems to lack substance and is mysterious or sinister: a shadowy figure in a black cape.