Select the most appropriate synonym of the given word. Insidious

The most appropriate synonym of the word insidious is crafty.

Insidious means "working or spreading in a hidden and usually injurious way." Crafty means "skilled in deceiving or outwitting others."

The other options are not as appropriate synonyms for insidious.

• Benevolent means "kind and generous."
• Sincere means "honest and genuine."
• Callous means "uncaring and unsympathetic."