1. impossible or very difficult to read because of poor handwriting, print quality, or damage
2. too boring, difficult, or poorly written to be read with interest or understanding

Examples

• The doctor’s handwriting was completely unreadable.
• The old manuscript had become unreadable due to water damage.
• His signature was an unreadable scrawl.
• The academic paper was so dense and jargon-filled that it was unreadable.
• The novel’s complex plot made it nearly unreadable for most students.
• The faded receipt was unreadable after being left in the sun.
• She found the legal document unreadable without a lawyer’s help.