'Grout' definitions:

Definition of 'grout'

noun

A thin mortar that can be poured and used to fill cracks in masonry or brickwork

verb

Bind with grout; "grout the bathtub"

From: GCIDE

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]

From: GCIDE

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]