Synonym
* Definition: A synonym is a word or phrase that has the same or nearly the same meaning as another word or phrase.
* Example:
* Happy: Joyful, cheerful, delighted
* Big: Large, enormous, huge
Antonym
* Definition: An antonym is a word or phrase that has the opposite meaning of another word or phrase.
* Example:
* Hot: Cold, freezing
* Happy: Sad, unhappy, miserable
In a nutshell:
* Synonyms are like "word twins" - they mean the same thing.
* Antonyms are like "word opposites" - they mean the opposite.