Etymology
Unknown, attested since the 1920s. Suggested origins, none of which are accepted by mainstream lexicographers, include:
* from Romani mol (“have value, be worth”)
* from Irish moll óir (“heap of gold”) However, this is unlikely because of the difference in pronunciation.
* from French moulin (“mill”)
* from Chinook Jargon moola (“mill”)
* from Sanskrit मूल्य (mūlya, “capital, principal”)
* coined by Chuck Green, a friend of Damon Runyon