In the manner or style of a blot; resembling a blot in character or appearance (rare literary term).
From blot plus -esque (suffix meaning 'in the style of,' from French/Italian origins), an unusual coinage that appears rarely in literature.
Blottesque is barely a real word—it's the kind of thing a creative writer might invent but dictionaries barely recognize, showing how English speakers constantly try to create new words even when existing ones work fine.
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