"Dredged up" is a phrasal verb that has two main definitions depending on the context in which it is used.
The first definition of "dredged up" refers to the act of bringing up or retrieving something from the bottom of a body of water, typically using a dredge. A dredge is a device or a vessel equipped with a scoop or a net that is lowered into the water to scoop up mud, sand, rocks, or other materials from the bottom. This process is commonly used in navigation and in the extraction of minerals, and it is an essential activity in maintaining the depth and navigability of harbors, rivers, and ports.
The second definition of "dredged up" is often used in a figurative sense and refers to the act of recalling or bringing to the surface something from the past, usually memories, emotions, or information. When something is "dredged up" in this manner, it often implies that the topic or information being recalled is unpleasant, unwanted, or long-forgotten. It can also connote a deliberate act of excavating or resurrecting something from one's memory or the past, sometimes for the purpose of revisiting or analyzing it.
Overall, "dredged up" can be used both literally and figuratively to describe the process of bringing something up or retrieving something that was submerged or buried, whether it be physical materials from the bottom of a body of water or memories and emotions from the depths of one's mind.
The word "dredged up" is a colloquial term that derives its etymology from the verb "dredge". The verb "dredge" dates back to the late 16th century and originally referred to the process of excavating or clearing out a body of water or a riverbed using a dredge, which is a kind of scoop or net. The term gradually extended its meaning to include activities such as searching or bringing something up from the depths, whether literal or metaphorical.
In the context of "dredged up", the word "dredged" is used figuratively to mean recalling or bringing up memories or emotions from the past, often ones that were forgotten or buried deep. Hence, when someone says they have "dredged up" something, they are typically referring to the act of reviving or resurfacing something that was hidden or forgotten.