The story
- Middle English · inherited from*flostren
- English todayfluster
The verb is probably from Middle English *flostren (implied in flostring, flostrynge (“agitation; blustering”)) from a Scandinavian (North Germanic) language; compare Icelandic flaustra (“to bustle”), flaustr (“a bustle; a hurry”). Compare Old English flustrian (“to weave, plait, braid”). The noun is derived from the verb.
Etymology from Wiktionary, CC BY-SA 4.0.