Nimrod
The term "Nimrod" originally comes from the Bible, where Nimrod is described as a mighty hunter and a king of ancient times. He is mentioned in the Book of Genesis and is often associated with the building of the Tower of Babel.
The transformation of "Nimrod" from a biblical figure to a term meaning someone who is not very intelligent is an interesting linguistic evolution. The change in meaning likely began in the United States in the early 20th century. In a Bugs Bunny cartoon from the 1930s, Bugs sarcastically refers to the hunter Elmer Fudd as "Nimrod," implying that Elmer is not a skilled hunter. Over time, this sarcastic use of "Nimrod" to mean a foolish or inept person became more widespread in popular culture.
It's worth noting that this usage of "Nimrod" is considered informal and somewhat derogatory. Many people are not aware of its biblical origins and only know it as a term to describe someone who is not very bright. As with many words and phrases, the meaning of "Nimrod" has evolved over time through popular usage, and its biblical origins have been largely forgotten in contemporary language.
Earlier on you will find the use of Nimrod as a figure of speech to describe a hunter, or in substitute of the word hunter. Instead of discussing our inexperienced younger hunter in Washington Irving's "A Tour on the Prairies," he calls them young Nimrods. Not as an insult, instead Nimrod is simply to mean "hunter," that they were inexperienced is not related to the use of the word.
Also, another author refers to a nimrod as a hunter of women, again, a substitute for hunter. In Ben Hecht’s and Gene Fowler’s 1932 play The Great Magoo it is written, "He’s in love with her. That makes about the tenth. The same old Nimrod. Won’t let her alone for a second."