What is a word that has a similar meaning to another word called?

A word that has a similar meaning to another word is referred to as a synonym. Synonyms enhance language by providing variety and nuance to expression, allowing for richer and more precise communication. For instance, words like "happy" and "joyful" are synonyms because they convey similar sentiments, even though they might carry slight differences in connotation.

In contrast, antonyms represent words that have opposite meanings (such as "hot" and "cold"), homonyms are words that sound the same but have different meanings (like "bare" and "bear"), and analogies are comparisons between two things that show how they are similar in certain aspects, rather than focusing on meaning alone. Thus, synonym accurately captures the concept of similarity in meaning we are seeking.