Lewis Short
circĭnus, i
* M.. = κίρκινος, 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.
Charlton T. Lewis, Charles Short, A Latin Dictionary