unreadable

adjective

1. not readable; undecipherable; scribbled: His scrawl was almost unreadable.
2. not interesting to read; dull; tedious; an unreadable treatise.
3. extraordinarily difficult to read or comprehend; obscure; incomprehensible: an unreadable dream; an unreadable expression.

adjective

1. illegible; undecipherable
2. difficult or tedious to read

adj.c.1810, of written material, “dull, distasteful,” from un- (1) “not” + readable. Meaning “illegible” is from 1830.