Picture a blotch as an irregular, undefined shape, not a precise spot. A blotch of sunlight danced on the wall, changing shapes with the clouds.
Pro Tip 2/3
Not Always Negative
Blotch refers to discoloration, which can be negative or positive depending on the context. The sky was a canvas with a blotch of beautiful orange hues at sunset.
Pro Tip 3/3
Informal Description
Use 'blotch' for informal descriptions, especially when precision is not needed. He couldn't help but laugh at the blotch of mustard on his friend's nose.