from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. See rhumb line.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A line on a surface (such as the Earth) that cuts all meridians at a constant angle (but not a right angle).
  • n. The path followed by a ship or aircraft that maintains a constant course by the compass.

from The Century Dictionary and Cyclopedia

  • n. A loxodromic line.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a line on a sphere that cuts all meridians at the same angle; the path taken by a ship or plane that maintains a constant compass direction


Greek loxos, slanting + Greek dromos, course.
(American Heritage® Dictionary of the English Language, Fourth Edition)
Back-formation from loxodromic. (Wiktionary)


  • Mercator also produced the first globe to have rhumb lines (1541), based on his observation that a ship sailing towards the same point of the compass would follow a curve called a loxodrome (also called a rhumb line or spherical helix).

    Mercator, Gerardus

  • In "De arte navigandi" he announced his discovery and analysis of the curve of double curvature called the rumbus, better known as loxodrome, which is the line traced by a ship cutting the meridians at a constant angle.

    The Catholic Encyclopedia, Volume 11: New Mexico-Philip

  • his vocabulary alone is worth the cover price - gantries, quinquireme, discalced, carrack, loxodrome, godown, scutch, so shrewd in his deployment of detail, so blessed with good luck and goodwill that we forget the conceit and just enjoy the ride.

    The Seattle Times

Wordnik is becoming a not-for-profit! Read our announcement here.


Log in or sign up to get involved in the conversation. It's quick and easy.

  • This is a feature of a Mercator projection of the Earth, and why such maps was useful in their day.

    November 6, 2009