cossist adjective 1noun 1forms 1 adjective1 •Pertaining to the cossists and their methods; cossic.Clavius's treatise is, first of all, reckoned as one of the textbooks of cossist algebra. — 1989 noun1 •(historical) A practitioner of proto-algebra in Renaissance and Early Modern Europe.So also were trained the Cossists and Rechenmeister of Germany in his tradition. — 2014 formscossists
