FrancophonIA/Vikidia-EnFr huggingface dataset:
A synonym is a word (or a phrase) which means the same thing as another word or phrase.[1][2]

Examples:

Synonyms can be nouns, verbs, adverbs or adjectives, but both words must be of the same part of speech. That means, only a noun can be a synonym of another noun, only a verb can be a synonym of another verb, and so on.

One can find sets of synonyms in a thesaurus, which is a book listing groups of related words.

Some words are near-synonyms, which have similar but not exactly the same meaning.

The word "synonym" dates back over 500 years, to late Middle English.[1] The term is derived from Latin from the Greek word sunōnumon, neuter form (used as a noun) of the adjective sunōnumos, from sun- meaning 'with' + onoma meaning 'name' in the Greek language.[1]

The meaning of the word has remained unchanged for all these centuries. There is even a saying, going back to 1892, "Once a synonym, always a synonym".[4]
The word has been taught to generations of English-language students and is commonly known by the general public. Many other languages have a similar word for "synonym" with the same or similar spelling.