Definition of: magnitude

(mag′nə·td, -tyd) noun
1. Great size or extent; grandeur; importance.
2. Math. That which is conceived of as measurable.
3. The property of having size or extent.
4. Astron. A measure of the relative brightness of a star, ranging from one for the brightest to six for those just visible to the naked eye. The standard of reference is the polestar, with a brightness 2.512 times greater than the one next below it; magnitudes greater than one on the scale are expressed as minus quantities. Compare LIGHT RATIO.
5. Largeness in respect to relation or effect. [<L magnitudo <magnus large] Synonyms: bigness, bulk, dimension, extent, greatness, hugeness, immensity, largeness, size, vastness. Antonyms: diminutiveness, littleness, pettiness, slightness, smallness.