Origin: 1490–1500; < AF; OF
tortureus. See torture, -ous 
Related forms: tor⋅tur⋅ous⋅ly, adverb
Usage note:
Torturous refers specifically to what involves or causes pain or suffering: prisoners working in the torturous heat; torturous memories of past injustice. Some speakers and writers use torturous for tortuous, especially in the senses “twisting, winding” and “convoluted”: a torturous road; torturous descriptions. Others, however, keep the two adjectives (and their corresponding adverbs) separate in all senses: a tortuous (twisting) road; tortuous (convoluted) descriptions; torturous (painful) treatments.
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