The Collaborative International Dictionary
Deleteriousness
Deleterious \Del`e*te"ri*ous\,
[LL. deleterius noxious, Gr. dhlhth`rios, fr. dhlei^sqai to hurt, damage; pro
akin to L. delere to destroy.] Hurtful; noxious; destructive; pernicious; as, a deleterious plant or quality; a deleterious example. -- Del`e*te"ri*ous*ly, adv. -- Del`e*te"ri*ous*ness, n.
Wiktionary
deleteriousness
n. The quality of being deleterious.