To ingrain grime or dirt which is difficult to remove into (something); also (more generally), to make (something) dirty; to soil.
An irregularly shaped area.
An uneven patch of color or discoloration.
A bright or dark spot on old film caused by dirt and loss of the gelatin covering the film, due to age and poor film quality.
A dark spot on the skin; a pustule.
Blotting paper.
Any of various crop diseases that cause the plant to form spots.
Imperfection; blemish on one’s reputation, stain.
To develop blotches, to become blotchy.
To mark with blotches.