GD

If someone starts an online chat session with GD, they're likely saying "good day." This acronym is a quite informal way to send a formal greeting.

If you'd like to answer GD with a different, semi-formal acronym of your own, you can reply with GAS. If you want to respond with something less formal but just as obscure, you can use HT or WU.

GD stands for "God d***," which is used to add emphasis to something, typically out of frustration. It is most often used online or in text messages.

The acronym is usually seen preceding another word that the sender is angry about. It could be an annoying person, a broken vehicle, a difficult class in school, an incompetent player on your favorite sports team, or another vexing thing.

GD is most often used by teenagers or young adults. However, be careful who you use it with since it is rude and rather juvenile.

Fans of the punk rock band Green Day may refer to it as GD. For example, you might see Green Day fans use this acronym in forums or on social media, when discussing GD and their music.

Typically, Green Day is comprised of singer and guitarist Billie Joe Armstrong, bassist and backup vocalist Mike Dirnt, and drummer Tré Cool. (Cool replaced previous drummer John Kiffmeyer.) The band has been active since 1987 and released several popular albums, including Dookie, American Idiot, 21st Century Breakdown, and Revolution Radio.