unreadable

:  not readable: such asa :  not decipherable :  illegible unreadable handwritingb :  impossible to read and understand :  incomprehensible … a flawed, unreadable, misleading bill that garnered support based on propaganda and clever—but false—talking points. — Marilyn M. Singletonc :  impossible to interpret The expression on her face was unreadable.d :  not enjoyable or interesting enough to engage the reader an unreadable novel