Insidiously

//ɪnˈsɪdi.əsli// adv

adv ·Rare ·Advanced level

Definitions

Adverb
  1. 1
    in an insidious manner
Adverb
  1. 1
    in a harmfully insidious manner wordnet

Example

More examples

"If only there were evil people somewhere insidiously committing evil deeds, and it were necessary only to separate them from the rest of us and destroy them. But the line dividing good and evil cuts through the heart of every human being. And who is willing to destroy a piece of his own heart?"

Etymology

From insidious + -ly.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.