deficiency, lack, want - the state of needing something that is absent or unavailable; "there is a serious lack of insight into the problem"; "water is the critical deficiency in desert regions"; "for want of a nail the shoe was lost"

calamity, catastrophe, tragedy, disaster, cataclysm - an event resulting in great loss and misfortune; "the whole city was affected by the irremediable calamity"; "the earthquake was a disaster"

the Great Calamity, the Great Hunger, the Great Starvation, the Irish Famine - a famine in Ireland resulting from a potato blight; between 1846 and 1851 a million people starved to death and 1.6 million emigrated (most to America)