Retro is a contemporary term used to describe things from a bygone era. It is often used in a postive sense, refering to quirky or attractive products that are no longer available.
For example, "Retro fashion" or "Retro Chic" may consist of outdated styles, such as tie-dye shirts from the 1970s, or poodle skirts from the 1950s.
... trying to make the gyro fall over.)
The axis of the gyroscope in the Dynabee is fixed to the spinning mass and it rests in a little groove inside the wrist exerciser ...