Readable is a term used to define the quality of written text that can be easily read and understood by the reader. Therefore, un-readable means the exact opposite of readable, and it refers to the level of difficulty that makes it impossible or challenging to comprehend the text. Some of the antonyms for un-readable include legible, clear, intelligible, comprehensible, lucid, and understandable. These words signify the ease with which one can read and comprehend the text without putting in extra effort. Unlike un-readable, they denote the quality of good writing, which is clear and unambiguous, and therefore easy to read and understand.