Food that is perishable will go bad quickly if you do not keep it cold or use it soon — milk, meat, fish, fresh fruit and vegetables. Shops, kitchens, and customs forms talk about “perishable goods.” The opposite idea is food that lasts, like rice, dried beans, or tins. You can also use it as a noun in the plural: “perishables,” meaning those foods. It is a practical, slightly official word (labels, fridges, shipping rules). At home people just say “it will go off,” “it doesn’t keep,” or “use it soon.” Though actually, perish itself means “to die” or “to be destroyed,” so perishable is “able to perish” — food that can spoil. People almost never use it for things that are not food, even though the pieces of the word would allow that.