The measure of something's size, especially in terms of width or breadth; largeness, magnitude.
The maximum absolute value of some quantity that varies.
The arc of the horizon between the true east or west point and the foot of the vertical circle passing through any star or object.
The maximum absolute value of the vertical component of a curve or function, especially one that is periodic.
The arc of the horizon between the true east or west point and the center of the sun, or a star, at its rising or setting. At the rising, 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.
The horizontal line which measures the distance to which a projectile is thrown; the range.
The class of scale or magnitude of any amount, where each class contains values of a fixed ratio (most often 10) to the class preceding it. For example, something that is 2 orders of magnitude larger is 100 times larger, something that is 3 orders of magnitude larger is 1000 times larger, and something that is 6 orders of magnitude larger is a million times larger, because 10² = 100, 10³ = 1000, and 10⁶ = a million.