to say what the meaning of something, especially a word, is
In the dictionary, "reality" is defined as "the state of things as they are, rather than as they are imagined to be".
Before I answer your question, could you define your terms a little more (= explain what you mean by the words you have used)?
The dictionary is a valuable resource to define unfamiliar words and expand your vocabulary.
In the scientific community, researchers work to define precise terms for clarity in communication.
During the lesson, the teacher asked each student to define a concept in their own words.
The software includes a feature that allows users to define custom shortcuts for increased efficiency.
