The word torturous originates from the Latin verb torquere, meaning "to twist." This root gave rise to tortura, signifying the act of twisting or torment, which entered English as "torture." The adjective-forming suffix -ous was appended to create "torturous," literally meaning "full of the quality of torture." While the physical act of twisting evolved into the general concept of inflicting severe pain, the modern sense has broadened further to describe anything that causes extreme mental or physical suffering or is agonizingly slow and difficult.

Structure: tortur (to twist, to torment) + ous (adjective suffix) - tortur: From Latin tortura (torment, twisting), from tortus, past participle of torquere (to twist). Functions as the core root conveying the sense of inflicting pain. - ous: A suffix of Latin origin (-osus) used to form adjectives meaning "full of" or "characterized by."