What term describes the action of flowing forth suddenly in great volume?

The term that describes the action of flowing forth suddenly in great volume is "gush." This word conveys a sense of rapid and abundant flow, whether it be a liquid or something more abstract, like emotion or information. For example, when one discusses water gushing from a broken pipe, it clearly depicts a significant and unrestrained outpouring.

In contrast, the other terms have distinct meanings that do not relate to the idea of a sudden volume of flow. "Gust" refers to a strong, brief burst of wind, while "graze" means to lightly touch or scrape the surface of something. "Hack" typically refers to cutting or breaking something in a rough manner, often used in a completely different context. Therefore, "gush" is the appropriate choice as it specifically captures the essence of a sudden and copious outflow.