WordPress at a glance
function is not described

delete_user_setting() WP 2.7.0

Delete user interface settings.

Deleting settings would reset them to the defaults.

This function has to be used before any output has started as it calls setcookie().

No Hooks.

Return

true/false/null. True if deleted successfully, false if not. Null if the current user can't be established.

Usage

delete_user_setting( $names );
$names(string) (required)
The name or array of names of the setting to be deleted.

Code of delete user setting: wp-includes/option.php VER 5.1.1

<?php
function delete_user_setting( $names ) {
	if ( headers_sent() ) {
		return false;
	}

	$all_user_settings = get_all_user_settings();
	$names             = (array) $names;
	$deleted           = false;

	foreach ( $names as $name ) {
		if ( isset( $all_user_settings[ $name ] ) ) {
			unset( $all_user_settings[ $name ] );
			$deleted = true;
		}
	}

	if ( $deleted ) {
		return wp_set_all_user_settings( $all_user_settings );
	}

	return false;
}