from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A device for measuring the length of curves, such as on a map.
from the GNU version of the Collaborative International Dictionary of English
- n. An instrument with a revolving wheel for measuring a curved line, as on a map.
from The Century Dictionary and Cyclopedia
- n. An instrument for measuring curved lines upon a map.
Sorry, no etymologies found.
Another method for measuring curvilinear map distances is to use a mechanical device called an opisometer.
These often included local, regional and nationwide plans that most needed an opisometer and a Rubik's Cube to decipher.