Synonyms for insidious
- adjective
Most common
Synonyms by meaning
Adjective
1. Dangerous — treacherous
dangerous, perfidious, treacherous, deceitful, cunning, sly, scheming, artful, traitorous, disingenuous, snaky, wily, fraudulent, false, tricky, crafty, crooked, foxy, guileful, designing, trickish, devious
2. Subtle
Other
Definitions
- adj. 1
Treacherous.
The battle was lost due to the actions of insidious defectors.
- adj. 2
Causing harm in a stealthy, often gradual, manner.
Related words
- Word family
- insidiously insidiousness
Example sentences
- dangerous You shouldn't have gone to such a dangerous place.
- treacherous The weather can be very treacherous at this altitude.
- deceitful I learned the hard way that silence can be deceitful.
- perfidious I discovered Troy's perfidious plans.
Popularity over time
| Word | 1850 → 2019 | Trend |
|---|---|---|
| insidious | steady | |
| dangerous | steady | |
| treacherous | rising | |
| deceitful | rising | |
| perfidious | steady |
Use in printed books, per decade from 1850 to 2019.
By length
- 3 letters
- sly1
- 4 letters
- arch1, foxy2, wily2
- 5 letters
- false1, snaky
- 6 letters
- subtle2, tricky2, crafty2, artful2
- 7 letters
- crooked2, cunning2, devious3
- 8 letters
- scheming2, guileful, trickish
- 9 letters
- dangerous3, designing3, deceitful3
- 10 letters
- diplomatic4, fraudulent3, pernicious3, traitorous3, perfidious
- 11 letters
- treacherous3
- 12 letters
- disingenuous5
The small number after each word is its number of syllables (foxy2 = 2 syllables).
In other languages
- Français
- insidieux
- Italiano
- insidioso
- Deutsch
- hinterhältig
- Català
- insidiós