(1):

(a.) Bent in different directions; wreathed; twisted; winding; as, a tortuous train; a tortuous train; a tortuous leaf or corolla.

(2):

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

(3):

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

(4):

(a.) Injurious: tortious.