WordPress at a glance
function is not described

wp_get_referer() WP 2.0.4

Retrieve referer from '_wp_http_referer' or HTTP referer.

If it's the same as the current request URL, will return false.

No Hooks.

Return

false/String. False on failure. Referer URL on success.

Usage

wp_get_referer();

Code of wp get referer: wp-includes/functions.php VER 5.0.3

<?php
function wp_get_referer() {
	if ( ! function_exists( 'wp_validate_redirect' ) ) {
		return false;
	}

	$ref = wp_get_raw_referer();

	if ( $ref && $ref !== wp_unslash( $_SERVER['REQUEST_URI'] ) && $ref !== home_url() . wp_unslash( $_SERVER['REQUEST_URI'] ) ) {
		return wp_validate_redirect( $ref, false );
	}

	return false;
}