perniciōsē adv.with comp.
perniciosus, destructively, ruinously, perniciously : multa perniciose sciscuntur in populis: perniciosius mereri.
pernĭcĭōsē, adv., v. perniciosus fin. ...
A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.