From Middle English blek (“ink”), from Old Norse blek (“black tint, ink”), from Old English blæc (“black tint or dye, ink”), from Proto-West Germanic *blak, from Proto-Germanic *blaką (“that which is black; blackness”).
Meanings
Any black fluid substance, as in blacking for leather, or black grease.
Þerfore ȝif oure prelatis or oþere prestis, whatevere þei ben, ben opinly blecked by sacrifise of maumetrie, as wiþ covetise, þat is opinly sacrifise of fals goddys, and oþere grete sinnes, as pride, symonye, and man-quellinge, glotonye, dronkenesse, and lecherie, by þe same skil tyþis or offringis shulde be wiþdrawyn from hem by Goddis lawe, and be ȝoven to poeure nedy men, at ensaumple of riȝtful Tobie. 1382, John Wycliffe, A Petition to the King and Parliament; republished as chapter 33, in Thomas Arnold, editor, Select English works of John Wyclif, volume 3, Oxford: Clarendon Press, 1869, Tobit i. 8., page 518: