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b-day

American  
[bee-dey] / ˈbiˌdeɪ /
Or b'day

noun

Informal.
  1. birthday.

    When's her b-day?


Usage

What does b-day mean? B-day is an informal shortening of birthday, as in We’re surprising Rami with a cake for his b-day tomorrow. B-day is normally used in very informal situations, such as texting and social media posts, especially with friends and family rather than with strangers or acquaintances. B-day is also written as b’day. It’s also occasionally written as b day or beeday. Example: Jenny invited me to her b-day party at that fancy restaurant, and I can’t wait!

Etymology

Origin of b-day

By shortening

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Happy b-day: Los Angeles turned 235 on Sept. 4.

From Los Angeles Times • Sep. 6, 2016

And a happy 11th b-day to your hair.

From US News • Jun. 14, 2016

“It’s your 35th b-day today,” the handwritten message says.

From New York Times • Sep. 10, 2014

He emailed me that spring, “doing your first c-section on your b-day adds a warm and fuzzy component to this whole med school thing.”

From Salon • Mar. 12, 2013

“Oh, I’m sorry to hear that. I was hoping to do an early b-day celebration with her and spend some quality time together,” Maxine says.

From "Piecing Me Together" by Renée Watson