bday en · NOUN Pronunciation /ˈbiːdeɪ/ (Southern-England) audio Meanings (Internet, abbreviation, alt-of) Abbreviation of birthday. alt of birthday Happy bday!I think last time we spoke we both kind of said some really nasty things that neither of us meant, like… you broke up with me… on my b-day. 2008, Lorene Scafaria, Nick and Norah's Infinite Playlist, spoken by Nick (Michael Cera): Forms SpellingFeaturesLabelsSource bdays Number=Plur lexicographic bdai alternative, rare lexicographic B-day alternative lexicographic b-day alternative lexicographic