mortiferous in English dictionary mortiferous Meanings and definitions of "mortiferous" deadly, fatal, lethal adjective (now rare) Causing spiritual death. [from 16th c.] adjective Causing physical death; deadly, fatal, lethal. [from 16th c.] more Grammar and declension of mortiferous mortiferous ( comparative more mortiferous, superlative most mortiferous) mortiferous (comparative more mortiferous, superlative most mortiferous) more Mortiferous Sample sentences with "mortiferous" Declension Stem Try again Available translations Italian Paite Chin Sambahsa Authors