insidiously

UK
/ɪnˈsɪdɪəsli/
US
/ɪnˈsɪdiəsli/
insidiouslyadverb
UK
/ɪnˈsɪdɪəsli/
US
/ɪnˈsɪdiəsli/
Translations
The disease spread insidiously through the population.
Болезнь коварно распространилась среди населения.
Definitions
In a gradual, subtle way, but with harmful effects.
The disease spread insidiously through the population, unnoticed until it was too late.