Prandium Peculiaris

2. See title.
5. Ordinal number.
6. In the PM, first word of phrase.
7. Having requested the pleasure of one's company.
9. Persons present at a particular event, function or meeting.
11. A most important person in an Irish family.
13. Not feeling or showing gratitude.
14. Meaningful pet name, sounds like ear.
15. As the rhyme goes, the day on which if a child is born, they will work hard for a living.
17. The department of the Government of Ireland for whom you used to work for!
19. All of us.
21. An intense feeling of deep affection.

1. Better, greater, or otherwise different from what is usual, just like you!
2. One of Dublin's finest hotel establishments, its reputation surely 'bourn' from hard work.
3. Suffering from decay.
4. Twenty plus three.
5. The action or fact of leaving one's job and ceasing to work.
8. A sudden loud noise.
10. Latin for: of or for the heart.
12. In the PM, second word of phrase.
16. A point, period, or step in a process or development.
18. Supportive structure for an equestrian.
20. See title.