mag·ni·tude (măgnĭ-td′, -tyd′)
a. Greatness of rank or position: "such duties as were expected of a landowner of his magnitude" (Anthony Powell).
b. Greatness in size or extent: The magnitude of the flood was impossible to comprehend.
c. Greatness in significance or influence: was shocked by the magnitude of the crisis.
a. The brightness of a celestial body on a numerical scale for which brighter objects have smaller values. Differences in magnitude are based on a logarithmic scale that matches the response of the human eye to differences in brightness so that a decrease of one magnitude represents an increase in apparent brightness by a factor of 2.512. Also called apparent magnitude.
b. A unit on such a scale of brightness.
a. A number assigned to a quantity so that it may be compared with other quantities.
b. A property that can be described by a real number, such as the volume of a sphere or the length of a vector.
4. Geology A measure of the amount of energy released by an earthquake, as indicated on the Richter scale.
[Middle English, from Old French, size, from Latin magnitūdō, greatness, size, from magnus, great; see meg- in the Appendix of Indo-European roots.]
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