The Collaborative International Dictionary
Lethiferous
Lethiferous \Le*thif"er*ous\ (l[-e]*th[i^]f"[~e]r*[u^]s), a. [L. lethifer, letifer, fr. lethum, letum, death + ferre to bear, to bring: cf. F. l['e]thif[`e]re.] Deadly; bringing death or destruction.
Wiktionary
lethiferous
a. (context obsolete English) deadly, lethal.
Usage examples of "lethiferous".
In the pattern of the current society, I would be ultimately held responsible for his lethiferous behavior, and in doing so, I would no longer be able to carry on my work.