insidiously
🇺🇸
/ɪnˈsɪdiəsli/
🇬🇧
/ɪnˈsɪdiəsli/
in a sneaky way that causes harm without being noticed
Insidiously, the disease spread throughout the community, causing many people to fall ill.
这个疾病悄悄地在社区中传播,导致许多人生病。