Greek to someone

(it's all) Greek to (one)

cliché (It is) completely unintelligible, as if it is written in a language that one does not speak. The phrase comes from Shakespeare's play Julius Caesar. Mom said these instructions are Greek to her and that we should show them to Dad. A: "Can you understand this error message?" B: "Sorry, Greek to me. You'd better ask one of the programmers."
See also: Greek
Farlex Dictionary of Idioms.

Greek to someone

n. something incomprehensible to someone; something as mysterious as Greek writing. I don’t understand this. It’s all Greek to me.
See also: Greek, someone
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • (it's all) Greek to (one)
  • Greek
  • Greek to
  • Greek to me
  • Greek to me, it's
  • it's all Greek to me
  • (it's) (all) Greek to me
  • be all Greek to someone
  • (good) black don't crack
  • customer is always right, the