Source : Webster's Revised Unabridged Dictionary (1913)

Grub \Grub\, v. i. [imp. & p. p. {Grubbed}, p. pr. & vb. n.
   {Grubbing}.] [OE. grubbin., cf. E. grab, grope.]
   1. To dig in or under the ground, generally for an object
      that is difficult to reach or extricate; to be occupied in
      digging.

   2. To drudge; to do menial work. --Richardson.

Source : WordNet®

grubbing
     See {grub}

grub
     v 1: ask for and get free; be a parasite [syn: {mooch}, {bum}, {cadge},
           {sponge}]
     2: search about busily
     [also: {grubbing}, {grubbed}]

grub
     n 1: informal terms for a meal [syn: {chow}, {chuck}, {eats}]
     2: a soft thick wormlike larva of certain beetles and other
        insects
     [also: {grubbing}, {grubbed}]