compass card

noun

Navigation.

1. a circular card with magnets attached to its underside, the face divided on its rim into points of the compass, degrees clockwise from north, or both, and floating or suspended from a pivot so as to rotate freely.

compass card

noun

1. a compass in the form of a card that rotates so that "0°" or "North" points to magnetic north

Word History and Origins

Origin of compass card¹

First recorded in 1870–75