Need to add a small portion of description to your WordPress nav_menu like above? Follow this simple step to do so.

Step 1 – add a custom walker to your functions.php

[php]
if( !class_exists(‘Custom_Description_Walker’) ):
////////////////////////////////////////////////////////////////////
// add description to wp_nav
///////////////////////////////////////////////////////////////////
class Custom_Description_Walker extends Walker_Nav_Menu {
/**
* Start the element output.
*
* @param string $output Passed by reference. Used to append additional content.
* @param object $item Menu item data object.
* @param int $depth Depth of menu item. May be used for padding.
* @param array $args Additional strings.
* @return void
*/
function start_el(&$output, $item, $depth, $args) {
$classes = empty ( $item->classes ) ? array () : (array) $item->classes;
$class_names = join(‘ ‘, apply_filters(‘nav_menu_css_class’,array_filter( $classes ), $item)
);

! empty ( $class_names )
and $class_names = ‘ class="’. esc_attr( $class_names ) . ‘"’;
$output .= "<li id=’menu-item-$item->ID’ $class_names>";

$attributes = ”;

! empty( $item->attr_title )
and $attributes .= ‘ title="’ . esc_attr( $item->attr_title ) .’"’;
! empty( $item->target )
and $attributes .= ‘ target="’ . esc_attr( $item->target ) .’"’;
! empty( $item->xfn )
and $attributes .= ‘ rel="’ . esc_attr( $item->xfn ) .’"’;
! empty( $item->url )
and $attributes .= ‘ href="’ . esc_attr( $item->url ) .’"’;

// insert description for top level elements only
// you may change this
$description = ( ! empty ( $item->description ) and 0 == $depth )
? ‘<small class="nav_desc">’ . esc_attr( $item->description ) . ‘</small>’ : ”;

$title = apply_filters( ‘the_title’, $item->title, $item->ID );
$item_output = $args->before
. "<a $attributes>"
. $args->link_before
. $title
. ‘<br /><span>’ . $description . ‘</span>’
. ‘</a> ‘
. $args->link_after
. $args->after;

// Since $output is called by reference we don’t need to return anything.
$output .= apply_filters(
‘walker_nav_menu_start_el’
, $item_output
, $item
, $depth
, $args
);
}
}
endif;
[/php]

Step 2 – add custom walker to your wp_nav_menu()

[php]
<?php wp_nav_menu( array( ‘theme_location’ => ‘primary’, ‘container’ => false, ‘menu_class’ => ‘sf-menu’, ‘fallback_cb’ => ‘revert_wp_menu_page’,’walker’ => new Custom_Description_Walker )); ?>
[/php]

add the ‘walker’ => new Custom_Description_Walker to your existed wp_nav_menu()

Step 3 – adding the description for each menu item

go to wp-admin -> appearance -> menu and click on the top right Screen Options and check (tick) the red description area

open any menu item and text into the description box like below

Step 4 – add some CSS to the description

in this case, the description was wrap inside a < span > so we need to add some extra CSS to span. example like below

[php]
.sf-menu a span { font-size: 10px !important; }
[/php]

Once every step completed, you should see a small description in each of your menu items.