"Greek to me" is an English idiom that describes something that is completely incomprehensible to the person who uses the expression. This phrase may be used when someone does not understand the manner of speech or the type of language he or she is hearing. In addition, it may be used to indicate that someone doesn't get the meaning of something that he or she experiences. The most famous usage of the phrase "Greek to me" and its likely origin is in the play "Julius Caesar," written by William Shakespeare in the 16th century.
An idiom is a phrase that is used by someone as a way to sound more colloquial or colorful to the people who are being addressed. In most cases, these idioms have accepted meanings that are far different than what they might have been when the expressions were first used. That's because extended usage within a culture transforms the meaning of an idiom to the point where it eventually has little similarity to the literal meaning of its words. One idiom that has survived for hundreds of years is the phrase "Greek to me."
The most common usage of this phrase comes when someone hears speech that he or she can't quite comprehend. He or she may listen and even be attentive, but the meaning is elusive. This could be because the words are from a different language or because the speaker uses slang that the listener fails to recognize. As an example, someone might say, "Those kids went on and on with all their schoolyard lingo but it was all Greek to me."
While that is narrowest usage of the phrase, its meaning can also expand to include any type of situation that is not understood by someone. This could be the case when something is a bit too complicated for someone, or when it represents something that he or she has never experienced before. For this type of usage, consider the sentence, "I consider myself pretty good with mathematical problems, but those advanced equations are all Greek to me."
William Shakespeare used this phrase in his famous tragedy "Julius Caesar." It came in the context of two men who were discussing the orator Cicero, who had spoken in Greek to an audience. When the person who had heard the speech was asked what Cicero had said, he replied that it was "Greek to me." Since the tragedy was set in Rome, the implication is that Greek was a language that only a few erudite men would speak. The rest of the population would not understand.