1. The plural of insidiousness; the quality of being insidious; the state of proceeding in a subtle, deceptive, or gradual manner that is harmful or dangerous.
Usage: Abstract noun; typically used in formal or academic contexts; Plural form emphasizes multiple instances or aspects of insidious behavior or qualities

Examples

• The insidiousnesses of propaganda lie in their ability to shape opinion without the audience's awareness.
• Historians debate the various insidiousnesses of colonial policies that appeared benign on the surface.
• The insidiousnesses of addiction make it difficult for people to recognize the problem until it is severe.
• Social media platforms have been criticized for the insidiousnesses of their algorithms in influencing user behavior.
• The insidiousnesses of systemic discrimination operate quietly, often invisible to those in positions of privilege.