Tortuous vs. Torturous

Tortuous (without the second r) means “winding, tricky, crooked, convoluted”:

tortuous roads caused the dog to become carsick and vomit on my shoes (true story)

tortuous legal jargon

tortuous plot

Torturous (from the noun and verb torture) means “painful” or “slow and difficult, labored”:

torturous feelings of guilt

tortuous English class¹

the rusty old car’s torturous climb up the steep hill

¹ Thanks to former student Tracy for this witty example.