Nonius, also known as Nonius Marcellus, was a Roman grammarian and scholar who lived during the 1st century BC. He is best known for his work, the "De Compendiosa Doctrina," which focused on the study of language and grammar. Nonius aimed to preserve and explain the intricacies of the Latin language, making his contributions significant for future generations of scholars. His name is also associated with the Nonius scale, a device used in navigation and engineering to measure angles and distances accurately. This scale, developed in the 16th century, is named after him due to its similarity to the principles he applied in his grammatical studies.