From names to wordsMyths & disputes
nimrod
Nimrod, 'a mighty hunter before the LORD', was a tyrant in Renaissance English and a byword for a keen hunter by 1712, as in French, German and Polish; in Islamic lore Namrūd is Abraham's persecutor, so Turkish 'nemrut' means a cruel, cantankerous man — and 20th-century Americans, probably through sarcasm, turned him into an idiot.
Weakest linkCertain
The story you may have heardBugs Bunny is said to have created the 'idiot' sense by mocking Elmer Fudd as a 'poor little Nimrod'. The cartoon uses are real but later and different. Daffy Duck calls Elmer 'my little nimrod' in What Makes Daffy Duck (1948), and Bugs calls Yosemite Sam 'the little Nimrod' in Rabbit Every Monday (1951). Both mean 'hunter', sarcastically. A 'nit-wit nimrod' appears in a newspaper ad the same year, 1948. The cartoons probably helped spread the insult to children who did not know Genesis, but they did not create it. Grade: popular, unproven as an origin.