insidiousness

Noun insidiousness has 2 senses

• insidiousness(n = noun.attribute) - subtle and cumulative harmfulness (especially of a disease);
is a kind of harmfulness, injuriousness
Derived form adjective insidious₃

• insidiousness(n = noun.attribute) - the quality of being designed to entrap;
is a kind of perfidiousness, perfidy, treachery
Derived forms adjective insidious₂, adjective insidious₁