There are several theories for the origin of the word hoodlum.
One has to do with a gang of thugs in San Francisco led by a man named Muldoon.
A fearful reporter, writing about him in 1877, spelled the name backward, Noodlum, and the compositor mistook the N for an H.
A second theory claims the word is derived from the Pidgin English hood lahnti, meaning “very lazy mandarin.”
The final theory, which comes from San Francisco, says that the many Germans living in the city simply mispronounced the Bavarian word for hoodlum, Hodalump.