Excess definition: the fact of exceeding exceeding something else in amount or degree.. See examples of EXCESS used in a sentence. Excess is too much of something, like big-time overindulgence. Eating to excess makes your stomach hurt, and spending to excess means you can't pay your credit card bills. Excess means an extreme amount or degree, or going beyond normal or permitted limits. Learn the synonyms, usage, and idioms of excess from various dictionaries and sources. The words excess and excessive might seem similar, but they are used differently. Excess is a noun. It means having more than needed or allowed. For example, “The project had an excess of volunteers.” Excessive, on the other hand, is an adjective. It describes something that is too much or too high. For example, “His excessive talking during the movie was annoying.” So, when you talk about more than what is necessary, use excess as a thing and excessive as a description.