Geom. [mod.L., f. SYN- + TRACTRIX.] The locus of a point on the tangent to a tractrix at a constant distance from its intersection with the axis. Also Syntractory [TRACTORY sb. 3].
1820. G. Peacock, Examples Diff. Calc., I. xxiii. 175. Syntractory.
1852. G. Salmon, Higher Plane Curves, III. (1879), 289. The syntractrix is the locus of a point Q on the tangent to the tractrix which divides into portions of given length the constant line SN.
