A person who studies or is a specialist in synonyms.

समानार्थी विशेषज्ञ

English Usage: The synonymist provided an extensive list of alternatives for the word "happy."

Hindi Usage: समानार्थी विशेषज्ञ ने "खुश" शब्द के लिए विकल्पों की एक विस्तृत सूची प्रदान की।