expression, i-adjective
illegible; indecipherable; hard to read
Describes handwriting, print, or characters that are difficult or impossible to decipher. Often used for messy or unclear writing.
彼のメモは判読しがたい。
His notes are illegible.
古い文書は判読しがたいことが多い。
Old documents are often hard to decipher.
読みにくい is a broader term for 'hard to read' (e.g., due to complex content or small font), while 判読しがたい specifically means the characters themselves are illegible or indecipherable.
Compound of 判読 (handoku, 'deciphering') + しがたい (shigatai, 'difficult to do'), from the verb 判読する (handoku suru, 'to decipher').