a. and sb. Math. [f. UNI- 1 + L. cursus course: see -AL.] a. adj. Having, traversing, or being on one course or path. b. sb. A unicursal curve.
1866. Cayley, in Proc. London Math. Soc., April. A unicursal curve is nothing else than a curve with a deficiency D = 0. Ibid. (1871), Math. Papers (1895), VIII. 388. On the Transformation of Unicursal Surfaces.
1873. G. Salmon, Higher Plane Curves, ii. 29. If the coordinates can be expressed as rational functions of a parameter the curve has the maximum number of double points. Curves of this sort are called unicursal curves.
Hence Unicursality; Unicursally adv.
1887. Amer. Jrnl. Math., X. 24. In the unicursality-equation a cusp plays the role of an ordinary double-point.
1892. W. W. R. Ball, Math. Recreat., 124. A figure is described unicursally when the whole of it is traversed in one route.
