1. Grief; sorrow; misery; heavy calamity. Thus saying, from her side the fatal key, sad instrument of all our woe, she took. (milton) They weep each other’s woe. (pope)
2. A curse; a malediction. Can there be a woe or curse in all the stores of vengeance equal to the malignity of such a practice? (south)
Woe is used in denunciation, and in exclamations of sorrow.