compass card

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A freely pivoting circular disk carrying the magnetic needles of a compass and marked with the 32 points of the compass and the 360 degrees of the circle.

from The Century Dictionary.

• noun The circular card belonging to a compass. See compass, 7.

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

• noun compass in the form of a card that rotates so that 0 degrees or North points to magnetic north