What is the difference between a synonym and an antonym?

1. synonym is a word that is opposite of a given word and an antonym is the same
as a given word.

2. synonym means the same as a given word and an antonym means the opposite
of a given word.

3. synonym is only found in a thesaurus and an antonym can be found in a dictionary.

4. synonym is the same as the definition of a given word and an antonym is similar
to the definition of a given word.

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