Synonyms are different words that have the same or similar meanings. They come in every part of speech, including nouns, verbs, adjectives, adverbs, and prepositions.
As a synonym example, let’s look at synonyms for good. As one of the most commonly used words, good has a lot of synonyms that mean the same or almost the same thing: fine, excellent, satisfactory, wonderful, superb, etc.
Notice how the meanings are not always identical; for example, excellent is a high degree of good, while satisfactory is more like a minimal amount of good.