# insidiously

> English word · Adverb · IPA /ɪnˈsɪdi.əsli/ · frequency rank #85,374

## Definitions
1. in an insidious manner

## Etymology
From insidious + -ly.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/insidiously