indecipherable

adjective

in·​de·​ci·​pher·​able ˌin-di-ˈsī-f(ə-)rə-bəl 

: incapable of being deciphered

indecipherable writing

an indecipherable message

indecipherably

ˌin-di-ˈsī-f(ə-)rə-blē 

adverb

Synonyms of indecipherable

• illegible

Examples of indecipherable in a Sentence

His handwriting is almost indecipherable.

after so many years the paper label in the drawer of the antique desk is indecipherable

Recent Examples on the Web

That standard still holds for his frequent barrages of boasts, insults, threats, grouses and indecipherable dispatches via Truth Social. — Lorraine Ali, Los Angeles Times, 13 Aug. 2026

Tubman is all but indecipherable, roughly limned with white paint and covered by red, black, and yellow smudges and drips. — Zachary Fine, New Yorker, 10 Aug. 2026

That shape, whose contour resembles both an indecipherable ideogram and a flat asymmetrical spaceship, shows Parsons’s inventive side. — John Yau, ARTnews.com, 24 July 2026

One of the most exciting uses of AI has to be helping historians and archaeologists decipher previously indecipherable or untranslatable ancient texts. — Jeremy Kahn, Fortune, 23 June 2026

Word History

First Known Use

1802, in the meaning defined above