magnitude

plural magnitudes

1. countableuncountableThe absolute or relative size, extent or importance of something.

   And on a programme of works of this magnitude, passengers will need to be mindful of the age-old maxim of 'no gain without pain'.

   2020 September 23, Paul Stephen, “East Coast upgrade: changes to schedule... but on schedule”, in Rail, page 31

2. countableAn order of magnitude.
3. countableuncountablemathematicsA number, assigned to something, such that it may be compared to others numerically
4. countableuncountablemathematicsOf a vector, the norm, most commonly, the two-norm.
5. A logarithmic scale of brightness defined so that a difference of 5 magnitudes is a factor of 100.
   1. uncountableastronomyThe apparent brightness of a star, with lower magnitudes being brighter; apparent magnitude
   2. countableastronomyA ratio of intensity expressed as a logarithm.

      Observations in the infrared domain allow one to penetrate the ~25-30 magnitudes of extinction present at visible wavelengths.

      2005, Andreas Eckart et al., The Black Hole at the Center of the Milky Way, →ISBN, page 71

6. countableuncountablegeographyA measure of the energy released by an earthquake (e.g. on the Richter scale).