When something has been in the freezer so long, that when you cook and eat it, it tastes like everything else that it shared the freezer with over the previous months/years. This is rarely a good thing. The taste of said food is known as freezer flavor.
It is a direct result of freezerburn in many cases, and in others, such as with ice cubes, can be a result of age.
While cleaning out the freezer, I found an unpackaged corn dog in the very back, covered in frost and hidden behind a Swanson dinner. Smiling at my good fortune, I microwaved it and took a bite. Unfortunately, the corn dog had been impregnated with Freezer Flavor, and tasted like onions, fish, rust, and grape popsicles.