insidious

Definition of Insidious in English :

1. insidious

beguiling but harmful

Example Sentences:
'insidious pleasures'

2. insidious

intended to entrap

3. insidious, pernicious, subtle

working or spreading in a hidden and usually injurious way

Example Sentences:
'glaucoma is an insidious disease'
'a subtle poison'

WordNet Lexical Database for English. Princeton University. 2010.

Insidious

adjective

1.

stealthy, subtle, cunning, or treacherous

2.

working in a subtle or apparently innocuous way, but nevertheless deadly

an insidious illness

adjective

1.

characterized by treachery or slyness; crafty; wily

2.

operating in a slow or not easily apparent manner; more dangerous than seems evident

an insidious disease

adj.

1. Working or spreading harmfully in a subtle or stealthy manner: insidious rumors; an insidious disease.

2. Intended to entrap; treacherous: insidious misinformation.

3. Beguiling but harmful; alluring: insidious pleasures.