Italian edit

Etymology edit

From laborioso +‎ -issimo.

Adjective edit

laboriosissimo (feminine laboriosissima, masculine plural laboriosissimi, feminine plural laboriosissime)

  1. superlative degree of laborioso
    1. very laborious
    2. very industrious or hard-working

Latin edit

Adjective edit

labōriōsissimō

  1. dative/ablative masculine/neuter singular of labōriōsissimus