Darken
wiktionary
From Middle English derkenen, dirkenen, from Old English *deorcnian, *diercnian(“to darken”), from Proto-West Germanic *dirkinōn(“to darken”), equivalent to dark + -en.
Cognate with Scots derken, durken(“to darken”), Old High German tarchanjan, terchinen(“to darken”), Middle High German terken, derken(“to darken”).
etymonline
darken (v.)
c. 1300, derken, "to make dark or darker, deprive of light;" early 14c. (intransitive), "to grow or become dark," from dark (adj.) + -en (1). The more usual verb in Middle English in both senses was simply dark, as it is in Chaucer and Shakespeare, and darken did not predominate until 17c. The Anglo-Saxons also had a verb sweorcan meaning "to grow dark."
Meanings "grow less white or clear, turn a darker color" and "render less white or clear" are from late 14c. Figurative sense of "render gloomy, sadden" is from 1742. To darken(one's) door (usually with a negative) "enter one's house as a visitor," usually with an implication of unwelcomeness, is attested from 1729.
