Noun: A blotch is a mark or stain, often irregular in shape.
Verb: To blotch means to mark or stain with blotches.
Here are some examples:
Noun:
* "There was a large, red blotch on his cheek."
* "The painting had several blotches of paint."
Verb:
* "The rain blotched the paint on the wall."
* "Her face was blotched with freckles."