Synonyms: insidious, pernicious, subtle
Definition: working or spreading in a hidden and usually injurious way
Usage: glaucoma is an insidious disease; a subtle poison
Similar words: harmful
Definition: causing or capable of causing harm
Usage: too much sun is harmful to the skin; harmful effects of smoking
Definition: difficult to detect or grasp by the mind or analyze
Usage: his whole attitude had undergone a subtle change; a subtle difference; that elusive thing the soul
Similar words: impalpable
Definition: imperceptible to the senses or the mind
Usage: an impalpable cloud; impalpable shadows; impalpable distinctions; as impalpable as a dream
Synonyms: subtle
Definition: able to make fine distinctions
Usage: a subtle mind
Similar words: perceptive
Definition: having the ability to perceive or understand; keen in discernment
Usage: a perceptive eye; a perceptive observation