Определение tractrix в Английский Язык Английский Язык словарь
The curve that satisfies the following property: That segment of the tangent line that lies between the point of tangency and a fixed line has length independent of the point of tangency chosen
A curve such that the part of the tangent between the point of tangency and a given straight line is constant; so called because it was conceived as described by the motion of one end of a tangent line as the other end was drawn along the given line