- insidious - beguiling but harmful; "insidious pleasures"
Antonym: unseductive (indirect, via seductive)
- insidious - intended to entrap
Antonym: safe (indirect, via dangerous)
- insidious, pernicious, subtle - working or spreading in a hidden and usually injurious way; "glaucoma is an insidious disease"; "a subtle poison"
Antonym: harmless (indirect, via harmful)