Italian edit

Etymology edit

From pernicioso +‎ -issimo.

Adjective edit

perniciosissimo (feminine perniciosissima, masculine plural perniciosissimi, feminine plural perniciosissime)

  1. superlative degree of pernicioso (very pernicious)

Latin edit

Adjective edit

perniciōsissimō

  1. dative/ablative masculine/neuter singular of perniciōsissimus