Source : Webster's Revised Unabridged Dictionary (1913)

Crumb \Crumb\ (kr[u^]m), n. [AS. cruma, akin to D. kruim, G.
   krume; cf. G. krauen to scratch, claw.] [Written also
   {crum}.]
   1. A small fragment or piece; especially, a small piece of
      bread or other food, broken or cut off.

            Desiring to be fed with the crumbs which fell from
            the rich man's table.                 --Luke xvi.
                                                  21.

   2. Fig.: A little; a bit; as, a crumb of comfort.

   3. The soft part of bread.

            Dust unto dust, what must be, must; If you can't get
            crumb, you'd best eat crust.          --Old Song.

   {Crumb brush}, a brush for sweeping crumbs from a table.

   {To a crum}, with great exactness; completely.