mottle

名词 mottle:

1. an irregular arrangement of patches of color

动词 mottle:

1. mark with spots or blotches of different color or shades of color as if stained
   同义词：streak, blotch
2. colour with streaks or blotches of different shades
   同义词：dapple, cloud

mot.tle

v.tr.（及物动词）
mot.tled,mot.tling,mot.tles
To mark with spots or blotches of different shades or colors.
使有杂色：使呈不同深浅或颜色的斑点或大片污渍
n.（名词）
A spot or blotch of color.
斑点：有色的污点或污渍
A variegated pattern, as on marble.
斑驳：斑驳的图案，如在大理石表面

来源：
Probably back-formation from motley
可能源自 motley的逆成词

【引伸】
mot.tler
n.（名词）