the.com/blot

means A dark mark or smudge — of ink, paint, or anything else — that spoils a surface, or, by extension, a flaw that mars a reputation or record.

from A murky one by word standards: 'blot' shows up in Middle English with no clean single ancestor. It's likely related to Old Norse words for a spot or patch of color, and it runs in a loose family with 'blotch' and 'blemish,' though none of these connections are nailed down tight. Sometimes a word just arrives already looking like the stain it describes.