'Darkening' definitions:

Definition of 'darkening'

adjective

Becoming dark or darker as from waning light or clouding over; "the darkening sky"

noun

Changing to a darker color [syn: blackening, darkening]

From: GCIDE

Darken \Dark"en\ (d[aum]rk"'n), v. t. [imp. & p. p. Darkened (-'nd); p. pr. & vb. n. Darkening (-n*[i^]ng).] [AS. deorcian. See Dark, a.]
1. To make dark or black; to deprive of light; to obscure; as, a darkened room. [1913 Webster]
They [locusts] covered the face of the whole earth, so that the land was darkened. --Ex. x. 15. [1913 Webster]
So spake the Sovran Voice; and clouds began To darken all the hill. --Milton. [1913 Webster]
2. To render dim; to deprive of vision. [1913 Webster]
Let their eyes be darkened, that they may not see. --Rom. xi. 10. [1913 Webster]
3. To cloud, obscure, or perplex; to render less clear or intelligible. [1913 Webster]
Such was his wisdom that his confidence did seldom darkenhis foresight. --Bacon. [1913 Webster]
Who is this that darkeneth counsel by words without knowledge? --Job. xxxviii. 2. [1913 Webster]
4. To cast a gloom upon. [1913 Webster]
With these forced thoughts, I prithee, darken not The mirth of the feast. --Shak. [1913 Webster]
5. To make foul; to sully; to tarnish. [1913 Webster]
I must not think there are Evils enough to darken all his goodness. --Shak. [1913 Webster]

From: GCIDE

Darkening \Dark"en*ing\, n. Twilight; gloaming. [Prov. Eng. & Scot.] --Wright. [1913 Webster]