A word that serves as a synonym to headwords is a noun, adjective, verb, or adverb.
A synonym is a word, or in some cases, a phrase that has the same meaning as another word with regards to the same language.
If the meaning is not exactly the same, the words have very similar meanings in the context.
When two words are synonyms of one another, we call them ‘synonymous words’
Using ‘jump’ as an example, the words ‘leap’, ‘bounce’, ‘hop’ are all synonymous to ‘jump’, i.e. they have the same (or very similar) meanings.
ANTONYMS
Now as opposed to a synonym, an antonym is a word whose meaning is exactly opposite to another word in the same language.
It originates from the Greek word ‘anti’, which stands for opposite and ‘onym’, which stands for ‘name’.
For example: the antonym for ‘hot’ is ‘cold’, and the antonym for ‘up’ is ‘down’
Antonyms are actually quite useful in the English language.
At times, it is easy to understand the meaning and the context of a difficult word, by knowing what the opposite of the word means.
For example: ‘mundane’, whose synonym is ‘humdrum’. The antonym for mundane is ‘extraordinary’ or ‘imaginative’; now, the word ‘mundane’ has a much better clarity.