fluster
Fluster (verb) means to make someone flustered, confused, or momentarily panicked.
Etymology
The verb probably comes from Middle English *flostren (implied by flostring, flostrynge (“agitation; blustering”)), from a Scandinavian (North Germanic) language; compare Icelandic flaustra (“to bustle”) and flaustr (“a bustle; a hurry”). Compare also Old English flustrian (“to weave, plait, braid”). The noun derives from the verb.