Something perishable is likely to die or decay. A perishable is also a type of food with a limited shelf life if it's not refrigerated.
Since perishing is dying, anything perishable could die or is likely to die. Unfortunately, people are perishable and most things in the world are too. Nothing lasts forever. A perishable is also a type of food that will go bad quickly if you leave it out of the fridge. Milk is a perishable, and so are yogurt and ice cream. Whether you're talking about a perishable or something perishable, this word refers to something that just won't last.