- gyromancy (n.)
- 1550s, method of divination said to have been practiced by a person walking in a circle marked with characters or signs till he fell from dizziness, the inference being drawn from the place in the circle at which he fell; from Medieval Latin gyromantia, from Greek gyyros "circle" (see gyro- (n.)) + manteia "divination, oracle" (see -mancy).
- gyroscope (n.)
- 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.
- gyroscopic (adj.)
- 1869, from gyroscope + -ic. Related: Gyroscopically.
- gyrostat (n.)
- instrument for illustrating the dynamics of rotation, 1868, from gyro- + -stat.
- gyrostatics (n.)
- branch of dynamics dealing with rotating bodies, 1883, from gyrostatic (1875); see gyrostat + -ics.
- gyrus (n.)
- convolution between grooves of the brain, 1827, from Latin gyrus "circle, circuit, career," from Greek gyros "a ring, circle" (see gyre (n.)).
