Definition of INSIDIOUS

insidious

Adjective Satellite

  • beguiling but harmful
    • "insidious pleasures"
  • intended to entrap
  • working or spreading in a hidden and usually injurious way
    • "glaucoma is an insidious disease"

Adj

  • Producing harm in a stealthy, often gradual, manner.
  • Intending to entrap; alluring but harmful.
  • Treacherous.

Examples

  • The battle was lost due to the actions of insidious defectors.

Origin / Etymology

From Middle French insidieux, from Latin īnsidiōsus (“cunning, artful, deceitful”), from īnsidiae (“a lying in wait, an ambush, artifice, stratagem”) + -ōsus, from īnsideō (“to sit in or on”), from in (“in, on”) + sedeō (“to sit”).

Synonyms

pernicious, subtle

Scrabble Score: 10

insidious: valid Scrabble (US) TWL Word
insidious: valid Scrabble Word in Merriam-Webster MW Dictionary
insidious: valid Scrabble Word in International Collins CSW Dictionary

Words With Friends Score: 12

insidious: valid Words With Friends Word