Invitation (noun)

1. A request to attend an event, or to go somewhere or do something.
2. A card or message requesting the pleasure of someone's company at a particular event.

Origin:

Mid 17th century: from latin invitatio(n-), from invitare 'to invite'.

Examples:

1. She received an invitation to a wedding.
2. He extended an invitation to his friends to join him for dinner.
3. The invitation to the royal palace was a great honor.
4. She cherished the invitation as a keepsake.
5. The invitation was written in beautiful calligraphy.