Correct spelling for the English word "jumbs" is [d͡ʒˈʌmz], [dʒˈʌmz], [dʒ_ˈʌ_m_z] (IPA phonetic alphabet).
There is no known word "jumbs" in the English language, and therefore there is no etymology available for it. It's possible that you might be referring to another word or made a typo. If you can provide more information, I'd be happy to help you further.