Meaning

verb become dark or darker

verb tarnish or stain

verb make dark or darker

originFrom 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”).

Etymology from Wiktionary, CC BY-SA 3.0