Antonyms of adj insidious

3 senses of insidious

Sense 1
insidious -- (beguiling but harmful; "insidious pleasures")

INDIRECT (VIA seductive) -> unseductive -- (not seductive)

Sense 2
insidious -- (intended to entrap)

INDIRECT (VIA dangerous) -> safe -- (free from danger or the risk of harm; "a safe trip"; "you will be safe here"; "a safe place"; "a safe bet")

Sense 3
insidious, pernicious, subtle -- (working or spreading in a hidden and usually injurious way; "glaucoma is an insidious disease"; "a subtle poison")

INDIRECT (VIA harmful) -> harmless -- (not causing or capable of causing harm; "harmless bacteria"; "rendered the bomb harmless")

Similarity of adj insidious

3 senses of insidious

Sense 1
insidious -- (beguiling but harmful; "insidious pleasures")
       => seductive (vs. unseductive) -- (tending to entice into a desired action or state)

Sense 2
insidious -- (intended to entrap)
       => dangerous (vs. safe), unsafe -- (involving or causing danger or risk; liable to hurt or harm; "a dangerous criminal"; "a dangerous bridge"; "unemployment reached dangerous proportions")

Sense 3
insidious, pernicious, subtle -- (working or spreading in a hidden and usually injurious way; "glaucoma is an insidious disease"; "a subtle poison")
       => harmful (vs. harmless) -- (causing or capable of causing harm; "too much sun is harmful to the skin"; "harmful effects of smoking")