holy crap

[kjc0123]

What is the meaning of "holy crap" and in which cases was it used?

[andy hughes]

It is just an exclaimation, and doesn't really mean anything. the use of the word 'holy' in an oath dates from early Christian times, when religion was far more a part of daily life, and invoking the notion of God or the church in everyday speech was far more common. Thus, someone might exclaim "Holy God!!" or "By all the saints!" if something good, or bad, happened.

Modern usage of evocative exclamations simply brings supposedly shocking additions - hence the phrase you quote. It doesn't actually mean anything literally, it is simply an excalimation, to be used carefully depending on the people within earshot.

[Kingaroo]

Well said, andy. And just in case a non-native speaker doesn't know, "crap" means sh*t, or fecal matter, or any kind of useless or annoying garbage.
"There's crap all over the dinner table" is probably referring to newspapers and dirty dishes. It's okay in casual speech, but use with care.