Mottle \Mot"tle\, v. t. [imp. & p. p. {Mottled}; p. pr. & vb. n. {Mottling}.] [From {Mottled}.] To mark with spots of different color, or shades of color, as if stained; to spot; to maculate. [1913 Webster]
mottling \mottling\ n. 1. the act of coloring with areas of different shades. [WordNet 1.5] 2. A mottled pattern. [PJC]