What it can not be read receives the qualification of unreadable . East adjective allows you to rate a text that, for some reason that goes beyond language comprehension, cannot be understood .

For example: "The doctor's prescription is illegible, nobody at the pharmacy managed to understand what he wanted to write", "The police found a letter at the scene of the crime, but it is illegible since the paper got wet and faded the ink", "The bettor did not receive his prize because the ticket he presented is illegible and the numbers cannot be verified".
A certain text may become illegible for multiple reasons. The most common is the poor clarity of the calligraphy . Whoever reads, in this framework, cannot discern the letters since they are poorly written, with confusing strokes.
A document may also become illegible by some kind of damage to its material support (paper, cardboard, etc.). If a glass of wine is spilled on the page of a book, the content may become illegible due to the effects of the liquid on the ink and on the paper .
That something becomes illegible can be a major problem. Suppose a man write and sign your will , detailing how you want your estate distributed once you are dead. When his death finally occurs, his lawyer goes to look for said will and finds that, as a result of the humidity of the place where it was stored, the text and the signature of the subject became illegible: there is no way to know what the deceased wrote or to prove if he is the true author of the will. That the document is illegible, therefore, is a great inconvenience.