An Etymological Dictionary of the German Language/Annotated/schwinden

by Friedrich Kluge

schwinden, verb, ‘to vanish, dwindle away, decay, perish,’ from Middle High German swinden, Old High German swintan, ‘to vanish, pass away, grow lean, become unconscious, faint’; corresponding to Anglo-Saxon swindan (wanting in English), ‘to vanish’; probably allied to a root swī̆ (like Gothic standan to the root stā̆?). The root swī̆ appears in Old High German swinan, Middle High German swînen, ‘to decrease, disappear, grow lean, become unconscious,’ Old Icelandic svína, ‘to subside,’ svía, ‘to abate,’ Old Icelandic svíme, Anglo-Saxon svîma, Dutch zwijm, ‘giddiness, vertigo.’ In the non-Teutonic languages the root swī̆, ‘to decrease,’ has not yet been authenticated; the comparison with Greek σί-νομας, ‘I plunder, damage,’ is dubious. —