unbirthday

• un-birthday

From un- +‎ birthday, coined by English writer Lewis Carroll (1832–1898) in Through the Looking-Glass (1871).

• (Received Pronunciation) IPA^(key): /ʌnˈbɜːθ.deɪ/
• (General American) IPA^(key): /ʌnˈbɝθ.deɪ/

• Audio (General Australian):

  (file)

• Hyphenation: un‧birth‧day

unbirthday (plural unbirthdays)

1. A day that is not one's birthday but is celebrated as though it were.
   • 1871 December 27 (indicated as 1872), Lewis Carroll [pseudonym; Charles Lutwidge Dodgson], “Humpty Dumpty”, in Through the Looking-Glass, and What Alice Found There, London: Macmillan and Co., →OCLC, pages 121–122:

     "They gave it me," Humpty Dumpty continued thoughtfully, as he crossed one knee over the other and clasped his hands round it, "they gave it me⸺for an un-birthday present." / "I beg your pardon?" Alice said with a puzzled air." / "I'm not offended," said Humpty Dumpty. / "I mean, what is an un-birthday present?" / "A present given when it isn't your birthday, of course."

   • 1995, Terry Orlick, Nice on My Feelings: Nurturing the Best in Children and Parents:

     Hunting for treasures on any special day (like Easter, Christmas, birthdays or unbirthdays) can be fun for children and parents alike.

   • 1998, Alison Molinare Boteler, Matthew Klein, The Disney Party Handbook: 14 Fun Filled Parties:

     Another way to look at unbirthdays is as an opportunity to celebrate every day of life. You can throw a party for no particular reason, except for FUN!

   • 2006, Sheila Ellison, 365 Games Smart Toddlers Play: Creative Time to Imagine, Grow and Learn:

     Make an unbirthday cake and wear party hats when you blow out the candles together.

   • 2007, Lisa Samson, Quaker Summer:

     I got some great photos with the unbirthday camera you left for me in the suitcase. Thanks.

   • 2008, Eleanor Hoyt Brainerd, Pegeen:

     "This is just an unbirthday party. Wait till you see your birthday party. When is your birthday, Peg?"