Noah Webster's New International Dictionary of the English Language

1. (a.) Bent in different directions; wreathed; twisted; winding; as, a tortuous path.

2. (a.) Fig.: Deviating from rectitude; indirect; erroneous; deceitful.

3. (a.) Injurious: tortuous.

4. (a.) Oblique; -- applied to the six signs of the zodiac (from Capricorn to Gemini) which ascend most rapidly and obliquely.