Merriam-Webster's Collegiate® Dictionary, 11th Edition
WOE
I. interjection
Etymology: Middle English wa, wo, from Old English wā; akin to Old Norse vei, interjection, woe, Latin vae Date: before 12th century — used to express grief, regret, or distress
II. noun Date: before 12th century a condition of deep suffering from misfortune, affliction, or grief, ruinous trouble ; calamity , affliction , see: sorrow