What does Earsplitting scream means if a idiom?

"Earsplitting scream" is not an idiom in the traditional sense. It's a simile, a figure of speech that compares two things using words like "like" or "as."

Meaning:

The phrase "earsplitting scream" describes a scream that is so loud and intense that it seems like it could literally split your eardrums. It's a vivid way to convey the sheer volume and power of the scream.

Example:

"The child let out an earsplitting scream when he saw the spider."

Note: While not an idiom, it is a commonly used and understood phrase in English.