Definition: Adjective: A descriptive noun or adverb that describes a thing, person, place, thing, or idea. Definition: 1. Descriptive noun or adverb: An adjective has a definite sense of describing a specific object or feature, such as "big," "red," "beautiful," "hot," etc. Example sentence: "I was very hot." This sentence uses an adverb to describe the temperature. 2. Describing things: An adjective describes something that is being described by another word. For example, "blue" describes the color of a sky. Example sentence: The blue sky was beautiful.