Source : Webster's Revised Unabridged Dictionary (1913)

Grout \Grout\, v. t. [imp. & p. p. {Grouted}; p. pr. & vb. n.
   {Grouting}.]
   To fill up or finish with grout, as the joints between
   stones.

Grout \Grout\, n. [AS. grut; akin to grytt, G. gr["u]tze,
   griess, Icel. grautr, Lith. grudas corn, kernel, and Z.
   groats.]
   1. Coarse meal; ground malt; pl. groats.

   2. Formerly, a kind of beer or ale. [Eng.]

   3. pl. Lees; dregs; grounds. [Eng.] ``Grouts of tea.''
      --Dickens.

   4. A thin, coarse mortar, used for pouring into the joints of
      masonry and brickwork; also, a finer material, used in
      finishing the best ceilings. Gwilt.

Source : WordNet®

grout
     n : a thin mortar that can be poured and used to fill cracks in
         masonry or brickwork
     v : bind with grout; "grout the bathtub"