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.
その病気が巧妙にコミュニティ全体に広がり、多くの人々を病気にかけてしまった。