"D:" is a commonly used emoticon that represents a face with a shocked or surprised expression. It consists of a capital "D" for a wide-open mouth and a colon ":" for eyes, conveying strong emotions like disbelief or horror. This emoticon is often used in digital communication, such as text messages and social media, to express reactions to unexpected news or events. In the context of online conversations, "D:" can also indicate feelings of disappointment or sadness. It serves as a quick way to communicate emotions without using words, making it popular among users of platforms like Twitter, Facebook, and Instagram.