[1] : The Collaborative International Dictionary of English v.0.48

magnitude \mag"nitude\, n. l. magnitudo, from magnus great.
   see master, and cf. maxim.
   1. extent of dimensions; size; -- applied to things that have
      length, breadth, and thickness.
      1913 webster

            conceive those particles of bodies to be so disposed
            amongst themselves, that the intervals of empty
            spaces between them may be equal in magnitude to
            them all.                             --sir i.
                                                  newton.
      1913 webster

   2. geom. that which has one or more of the three
      dimensions, length, breadth, and thickness.
      1913 webster

   3. anything of which greater or less can be predicated, as
      time, weight, force, and the like.
      1913 webster

   4. greatness; grandeur. "with plain, heroic magnitude of
      mind." --milton.
      1913 webster

   5. greatness, in reference to influence or effect;
      importance; as, an affair of magnitude.
      1913 webster

            the magnitude of his designs.         --bp. horsley.
      1913 webster

   6. astron. see magnitude of a star, below.
      pjc

   apparent magnitude

   1. opt., the angular breadth of an object viewed as
      measured by the angle which it subtends at the eye of the
      observer; -- called also apparent diameter.

   2. astron. same as magnitude of a star, below.

   magnitude of a star astron., the rank of a star with
      respect to brightness. about twenty very bright stars are
      said to be of first magnitude, the stars of the sixth
      magnitude being just visible to the naked eye; called also
      visual magnitude, apparent magnitude, and simply
      magnitude. stars observable only in the telescope are
      classified down to below the twelfth magnitude. the
      difference in actual brightness between magnitudes is now
      specified as a factor of 2.512, i.e. the difference in
      brightness is 100 for stars differing by five magnitudes.
      1913 webster +pjc
see also:
master maxim magnitude of a star apparent magnitude apparent diameter magnitude of a star 
visual magnitude apparent magnitude magnitude 

Fixed Star >> F Words
Fixed Star, definition of term: Fixed Star
fixed+star_pag1.html

Giant Star >> G Words
Giant Star, definition of term: Giant Star
giant+star_pag1.html

Falling Star >> F Words
Falling Star, definition of term: Falling Star
falling+star_pag1.html

Double Star >> D Words
Double Star, definition of term: Double Star
double+star_pag1.html

Death Star >> D Words
Death Star, definition of term: Death Star
death+star_pag1.html

Dog Star >> D Words
Dog Star, definition of term: Dog Star
dog+star_pag1.html

Bronze Star >> B Words
Bronze Star, definition of term: Bronze Star
bronze+star_pag1.html