Dashicons is the official icon font of the WordPress.
There are two ways.
1. Custom code in function.php
add_action('wp_enqueue_scripts', 'ec_disable_dashicons');
function ec_disable_dashicons(){
if(!is_user_logged_in()) {
wp_dequeue_style('dashicons');
wp_deregister_style('dashicons');
}
}
2. Using EC Addons
