An Etymological Dictionary of the German Language/strack

by Friedrich Kluge

strack, adj., ‘extended, direct, tense,’ from MidHG. strac (ck), ‘straight, tight,’ to which ModHG. stracks, adv., ‘straightway, immediately,’ from MidHG. strackes, is allied; so too ModHG. strecken, ‘to stretch, extend.’