2π
β
It has no intrinsic meaning.
The underscore is just a character that is valid in JavaScript identifiers.
const _ = {
hello: function() {
console.log("Hello!");
}
};
_.hello();
The code you are looking at could assign any value to it.
It might be the underscore library. It might be the lodash library. It might be something else entirely.
Source:stackexchange.com