Custom Field and Invoice Printing

I have the following issue,

I need to add items names with another language such as Arabic, it have created custom field in item and called it arabic_name and added the arabic names of the items using this.

but i need to call it in printing format i have noticed with that there are loop in the printing format 

         {%- for item in doc.items -%}
                {{ item.item_code }}
                {%- if item.item_name != item.item_code -%}
                    <br>{{ item.item_name }}            

                {%- endif -%}
            <td class="text-right">{{ item.qty }}<br>@ {{ item.get_formatted("rate") }}</td>
            <td class="text-right">{{ item.get_formatted("amount") }}</td>
        {%- endfor -%}

I need to call it as same as {{ item.item_name }} to be {{ item.arabic_name }}

@Tarek_Esmail you can translate string by using frappe translate function

{{ _(item.item_name) }}

I need to use the custom field which i was defined, also need to know how i can define the item name in translation ?