The phrase is referring to something that is unintelligible. It's usually attributed to William Shakespeare, even it had been used the year before Shakespeare wrote his 'Julius Caesar', in 1600 by another Elizabethan playwright, Thomas Dekker. Actually it comes from a Medieval Latin proverb 'Graecum est; non potest legi' ('It is Greek; it cannot be read').

Übersetzung:

das sind (für mich) böhmische Dörfer

Gegenteil(e)

The opposite of "it's all Greek to me" is "it's comprehensible".

Synonym(e):

You could also say: I don't understand.