Synonyms for

Insidious

Verb / ˌɪˈnsɪˌdi:ʌs / Another word for insidious — explore alternatives below. For syllable breakdowns and pronunciation, see this word on Syllablesworld.

Definition

intended to deceive or entrap; sly, treacherous

Synonyms & similar words

subtle pernicious deceitful sneaky deceptive treacherous crafty cunning sly underhanded tricky dishonest fraudulent manipulative subtle sly shifty scheming beguiling double-dealing cagey perfidious

Synonyms by register

Formal

subtle stealthy deceitful treacherous

Informal

sneaky underhanded shady cunning

Literary

creeping insinuating

Antonyms

overt obvious direct apparent straightforward transparent aboveboard

Common collocations

  • insidious disease
  • insidious influence
  • insidious attack
  • insidious nature
  • insidious plot
  • insidious effect
  • insidious spread

Word family

adjective insidious
adverb insidiously

Usage note

Often used to describe something harmful that develops gradually and subtly, making it difficult to detect. It carries a negative connotation of being deceitful or treacherous.

Example sentences

  1. The insidious spider spun a web to trap its prey.
  2. The insidious plan was to steal the jewels without getting caught.
  3. The insidious virus spread quickly through the school.
  4. The insidious politician promised to lower taxes, but really raised them.
  5. The insidious teacher gave us a pop quiz on material we hadn't covered yet.

Quotes

  • The insidious nature of our enemy means we must be vigilant at all times.
  • The insidious effects of poverty can be seen in every corner of the world.
  • The insidious lure of power can corrupt even the most noble of leaders.

Try these popular words

the and that for you with was this are have not from

Practice

Play the Word Synonyms game · Choose level (start near 1)

Worksheets

Grade 4 · Grade 5 · Grade 6

Topics

Guides

Explore more words