magnetic compass

magnetic compass (plural magnetic compasses)

1. (military, nautical) An instrument containing a freely suspended magnetic element which displays the direction of the horizontal component of the Earth’s magnetic field at the point of observation.
2. A supposed organ, in some animals, that allows then to align themselves with the Earth's magnetic field.

• compass (abbreviation)

• “magnetic compass” in the Collins English Dictionary, Glasgow: HarperCollins Publishers.
• “magnetic compass” (US) / “magnetic compass” (UK) in Oxford Dictionaries, Oxford University Press.
• “magnetic compass” in Merriam–Webster Online Dictionary.
• JP 1-02 Department of Defense Dictionary of Military and Associated Terms
• Page 673, Webster's II New College Dictionary
• Page 215, The Military Dictionary, DIANE Publishing, 1987
• Page 425, A dictionary of Science, Literature and Art, William Thomas Brande, 1866 (plural form is defined)