an imaginary line on the surface of a sphere, such as the earth, that intersects all meridians at the same angle
2.
the course navigated by a vessel or aircraft that maintains a uniform compass heading
Often shortened to: rhumb
Word origin
C16: from Old Spanish rumbo, apparently from Middle Dutch ruum space, ship's hold, but also influenced by Latin rhombus
rhumb line in American English
the course of a ship that keeps a constant compass direction, represented on a map, chart, or globe by a line that cuts across all meridians at the same angle