Lewis Short
aggĕrātĭo | adg- (noun F) : (), , 1. aggero
* A heaping up; in concr., that which is heaped up, a mole, dike (not before the Aug. per.): naves supra adgerationem, quae fuerat sub aquā, sederunt,Vitr. 10, 22, 263; Just. 2, 1 fin.
Charlton T. Lewis, Charles Short, A Latin Dictionary