- gyroscope (n.)
[gyroscope 词源字典]
- heavy rotating wheel with an axis free to turn in any direction, 1853, improved and named in French 1852 by Foucault, from Greek gyros "a circle" (see gyre (n.)) + skopos "watcher" (see scope (n.1)), because the device demonstrates that the earth rotates.[gyroscope etymology, gyroscope origin, 英语词源]