The name Nimrod come from the Hebrew נמרד or נמרוד (nimrod, pronounced nim-ROHD), where it is the name of Noah’s great-grandson through Ham (Genesis 10:8–14). This name most likely comes from the Semitic root מרד (mered), which means "to rebel," so Nimrod likely means "rebel." It may be related to the Sumerian name Ninurta, the Assyrian god of hunting and warfare.

Nimrod and Esau are the only two biblical characters that are described as "great hunters" (Genesis 10:9; 25:27). This connection would prove fateful for the name Nimrod in the United States. Esau was typically depicted as "dimwitted" for "despising his birthright in Genesis 25:29–34. Later, Bugs Bunny would use the name Nimrod in cartoons to refer to the "oafish hunter" Elmer Fudd, which cemented its English alternate meaning of "fool."