| 释义 |
torsal, a. Geom.|ˈtɔːsəl|
[f. torse3 + -al1.]
Of or pertaining to a torse: see quot.
1869Cayley Math. Papers VI. 334 If there is at each point of the line one and the same tangent plane, then the section of the surface by the tangent plane contains the line at least twice; if it contain it twice only, the line is torsal; if three times the line is oscular, and the tangent plane containing the torsal or oscular line may in like manner be termed a torsal, or an oscular tangent plane. |