AM'PLITUDE, noun [Latin amplitudo, from amplus, large.]
1. Largeness; extent, applied to bodies; as, the amplitude of the earth.
2. Largeness; extent of capacity or intellectual powers; as, amplitude of mind.
3. Extent of means or power; abundance; sufficiency.
Amplitude, in astronomy, is an arch of the horizon intercepted between the east and west point, and the center of the sun or star at its rising or setting. At the rising of a star, the amplitude is eastern or ortive; at the setting, it is western, occiduous, or occasive. It is also northern or southern, when north or south of the equator.
Amplitude of the range, in projectiles, is the horizontal line subtending the path of a body thrown, or the line which measures the distance it has moved.
Magnetical amplitude is the arch of the horizon between the sun or a star, at rising or setting, and the east or west point of the horizon, by the compass. The difference between this and the true amplitude is the variation of the compass.