Wiktionary
a. Not writable.
Usage examples of "unwritable".
Sometimes he allowed himself to believe it was simply an unwritable book and then his futile attempts to produce something were draped in nobility.
History-as-something-experienced being unwritable, we must perforce be content with history-as-something-in-the-minds-of-historians.
While we stuffed ourselves, he listened to our anguished stories about unwritable papers and unbearable crushes, providing kindness, advice and affirmation along with sustenance.
The program had a number of familiar commands, and some that were new: it set permissions on the log files to unwritable, deleted the last line of the log file, engaged all diagnostic programs, updated size and hash information on all alarms, copied her executive file over the old one, altered the dates of creation and modification on her new file to those of the old one, then ended all diagnostic programs and reset permissions on the log files to writable.