A grammatist is someone who is an expert in grammar, who has a deep understanding of the rules and conventions of language. However, there are several other words that can be used as synonyms for this term. For instance, a linguist is someone who studies language, including grammar, morphology, syntax, and phonetics. Another synonym is an etymologist, who studies the origins and history of words. A lexicographer is someone who compiles dictionaries, while a philologist studies language in its historical and cultural contexts. Other synonyms include a grammarian, a language scholar, and a semiotician, who studies signs and their meanings.