In a manner that is gradually harmful or deceptive.

ऐसा तरीका जो धीरे-धीरे हानिकारक या धोखेबाज़ हो।

English Usage: The disease progressed insidiously, showing few symptoms at first.

Hindi Usage: बीमारी धीरे-धीरे बढ़ी, शुरू में कुछ लक्षण दिखाई नहीं दिए।

A state of being deceptive or sly in order to achieve a goal.

धूर्तता

English Usage: His guilefulness allowed him to navigate the tricky negotiations successfully.

Hindi Usage: उसकी धूर्तता ने उसे कठिन बातचीत को सफलतापूर्वक संभालने की अनुमति दी।