Lewis & Short

pĕremptālis, e, adj. [peremptus], of or belonging to destruction or abolition, abolishing, cancelling; only in augural lang., fulmina, lightnings that destroy the effect or portent of former lightnings: peremptalia fulgura Gracchus ait vocari, quae superiora fulgura aut portenta vi suā perimant, Fest. p. 214 Müll.: peremptalia fulmina, quibus tolluntur priorum fulminum minae, Sen. Q. N. 2, 49, 2.