Synonyms for insidious

Adjective

1. insidious, seductive (vs. unseductive)

usage: beguiling but harmful; "insidious pleasures"

2. insidious, dangerous (vs. safe), unsafe

usage: intended to entrap

3. insidious, pernicious, subtle, harmful (vs. harmless)

usage: working or spreading in a hidden and usually injurious way; "glaucoma is an insidious disease"; "a subtle poison"