artificial horizon

Noun

 * 1)  An instrument that displays the pitch and roll of an aircraft in flight by comparing its attitude to a gyroscopically-maintained indication of the flat horizon line.
 * 2)  A small trough containing mercury, the surface of which shows a reflection of the celestial bodies.
 * 1)  A small trough containing mercury, the surface of which shows a reflection of the celestial bodies.

Translations

 * Portuguese: horizonte artificial
 * Russian: