Definition of it's (all) Greek to me in US English:

it's (all) Greek to me

phrase

informal
  • I can't understand it at all.

    • ‘As for Panathinaikos… well, it's all Greek to me.’
    • ‘On close examination, some of the numbers or symbols (it's all Greek to me) had been rubbed out with a finger and replaced.’
    • ‘‘I didn't know what they were… it's all Greek to me,’ he joked.’
    • ‘Yeah, yeah, I know - man the noble athlete still carrying the torch and all that - but to be honest it's all Greek to me.’
    • ‘As I would say constantly throughout my first year of high school, "it's all Greek to me."’