"Gah" is an exclamation often used to express frustration, annoyance, or surprise. It is a versatile interjection that can convey a range of emotions, from mild irritation to exasperation. People might say "gah" when they encounter something unexpected or when they are overwhelmed by a situation. This expression is commonly found in informal conversations, social media, and popular culture. It is frequently used in comic strips, television shows, and movies to depict characters' reactions. The simplicity of "gah" makes it an effective way to communicate feelings without needing a lengthy explanation.