Staple Crop: A food that is eaten routinely and makes up a significant proportion of a diet and supplies large amounts of energy and nutritional value.
Columbian Exchange: As mentioned earlier, this refers to the exchange of goods between Old World (Europe) and New World (Americas). Potatoes are one such good that was transferred from New World to Old world during this exchange.
Famine: Extreme scarcity of food. For example, when potato crops failed in Ireland during mid-19th century it led to Great Famine causing mass starvation.