Wordnet 3.0
NOUN (1)
1. 
 a thin mortar that can be poured and used to fill cracks in masonry or brickwork; 
VERB (1)
1. 
 bind with grout; 
- Example: "grout the bathtub"
The Collaborative International Dictionary of English v.0.48:
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.
   [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Grout \Grout\ (grout), n. [AS. gr[=u]t; akin to grytt, G.
   gr["u]tze, griess, Icel. grautr, Lith. grudas corn, kernel,
   and E. groats.]
   1. Coarse meal; ground malt; pl. groats.
      [1913 Webster]
   2. Formerly, a kind of beer or ale. [Eng.]
      [1913 Webster]
   3. pl. Lees; dregs; grounds. [Eng.] "Grouts of tea."
      --Dickens.
      [1913 Webster]
   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.
      [1913 Webster]
WordNet (r) 3.0 (2006):
grout
    n 1: a thin mortar that can be poured and used to fill cracks in
         masonry or brickwork
    v 1: bind with grout; "grout the bathtub"