flacker

From Middle English flakeren (“to flutter, waver”), frequentative of Middle English flaken (“to move quickly back and forth”), equivalent to flack +‎ -er. Akin to Old Dutch flakkeren (“to flicker, waver”), German flackern (“to flare, flicker, flutter”), Icelandic flökra (“to flutter”), Icelandic flakka (“to rove about”), Old English flacor (“flying, fluttering”). See also flack, flicker.

Alternatively, the Middle English word may descend from Old English *flacorian, a derivative of Old English flacor (“flickering, fluttering”).

flacker (third-person singular simple present flackers, present participle flackering, simple past and past participle flackered)

1. (intransitive) To flutter like a bird.
   • Bible, Ezekiel x. 19 (Coverdale's translation)

     And the cherubins flackered with their wings.

2. (intransitive) To flicker; to quiver.

• Fackler

flacker

1. First-person singular present of flackern.
2. Imperative singular of flackern.