pestilenter

pestilenter [LL] , in a manner that brings destruction, destructively. ~enter, ~entius, ~entissime adverbia Osb. Glouc. Deriv. 436; eo ~encius in obsessos sui furoris intendebat ‥ fulmina quo novit ibidem genitorem suum proditoria fraude circumventum ‥ extinctum fuisse Ps.-Elmh. Hen. V 93 p. 271.