Circinus, circini, pen. cor Pli. An instrumÊt called a compasse.Cícino, circinas, pen. cor. circiuâre. Plin. To make a circle with a compasse.Circinâta rotunditas. Plin. Circinâtus orbis. Plin. Circinare.Ouid.To compasse: to turne rounde.
Lewis and Short: Latin dictionary
circĭnus, i, m.. = ki/rkinos, a pair of compasses' flumen Dubis. ut circino circumductum, paene totum oppidum cingit, Caes. B. G. 1, 38: diducere, Vitr. 9, 7, 2: circino spatia dimetiri, id ib.; id. 10, 4, 1: ratio circini, Plin. 2, 15, 13, 63.
