The absolute or relative size, extent or importance of something. (noun)
An order of magnitude. (noun)
A number, assigned to something, such that it may be compared to others numerically (noun)
Of a vector, the norm, most commonly, the two-norm. (noun)
The apparent brightness of a star (on a negative, logarithmic scale); apparent magnitude (noun)
A measure of the energy released by an earthquake (e.g. on the Richter scale). (noun)
Examples of word magnitude
If city officials, movers, and shakers made as few mistakes in magnitude and number as Mr. Weston did in his letter, there'd be a lot less grief in Mudville, and Adams never would have made the team.
To give a few examples (in current $, numbers vary by source, but the order of magnitude is always the same):
The Mount Toba incident, although unprecedented in magnitude, was part of a broad pattern.
And the Post also forgot to tell its readers that the bad tax stuff is much larger in magnitude than the bad spending stuff they get rid of.
"The problem is just so huge in magnitude that there's no viable solution that can come out of the government to solve it," said Anthony Sanders, a finance professor at George Mason University.