Lewis Short
impĭĕtas | inp- (noun F) : (), , impius
* Want of reverence or respect, irreverence, ungodliness, impiety, undutifulness, disloyalty (rare but class.): nihil est quod tam miseros faciat quam impietas et scelus,Cic. Fin. 4, 24, 66; Ov. M. 4, 4: impietatis duces, of disloyalty, treason to one's country, Cic. Lael. 12, 42: impietatem punire voluit (legum lator),i. e. undutifulness to parents,Quint. 7, 1, 52; Suet. Vit. Luc.; cf. Ov. M. 8, 477: Albucilla defertur impietatis in principem,of high-treason,Tac. A. 6, 47; Plin. Pan. 33, 3.
Charlton T. Lewis, Charles Short, A Latin Dictionary