Definition of the word plunge in

The phrase "plunge in" is an idiomatic expression that means to begin or immerse oneself quickly and completely in an activity, task, or situation, typically without hesitation or reservation. It originated in the mid-19th century and is believed to have originated from the nautical term "plunge" which means "to jump or dive into water." In the context of sailing, "plunge" was used to describe the act of jumping overboard or descending into the water from a ship. This usage gave rise to an extended meaning in which "plunge" came to be used to generally mean "to dive headfirst into something." As the nautical expression became more widespread in reference to both literal and figurative situations, "plunge" came to be associated with the idea of entirely immersing oneself in a new activity or experience. Today, the alteration "plunge in" is widely used in the English language to indicate a prompt and decisive approach to embarking on a new project, action, or idea. In summary, the origin of the idiom "plunge in" can be traced back to the seaside and the nautical term "plunge," which gave rise to a broader meaning that is now commonly used in everyday speech to describe a quick and thorough beginning to something new.