A vat is a big container for holding liquids. If you're having a big party, your mom may get you to help cook a vat of spaghetti sauce to feed all your hungry relatives.
Here is an easy way to remember that vat has a short a sound: If you eat the whole vat, you'll probably get fat. Remember, though, that vats are not always food-related. People who make pottery, for example, keep vats of glazes in which they dip their vases and cups in order to color them. No matter what a vat contains, it's often heavy and hard to move.
