Insidious

Operating or proceeding in an inconspicuous or seemingly harmless way but actually having a gradual and cumulative effect; treacherous and deceitful. Something Insidious often spreads or develops slowly and subtly, making it difficult to detect its harmful nature until significant damage has been done. It can apply to diseases, plans, rumors, or even aspects of a person's character. The key element is the deceptively harmless facade that hides a dangerous or corrupting influence.

Insidious meaning with examples

• The Insidious nature of the disease meant that many people were unaware they were infected until the symptoms became severe, making it harder to treat effectively at later stages.
• The company employed an Insidious marketing strategy, subtly manipulating consumers into believing they needed their product, even if it was of little real value or necessity.
• Gossip, with its Insidious reach, can slowly poison relationships and erode trust within a community, leaving lasting scars on those who are targeted.
• The Insidious erosion of civil liberties, one small restriction at a time, ultimately resulted in a society far removed from its original ideals of freedom and justice.