[origin unknown] /MAWNG goh/
New York City dialect term for
an object retrieved from rubbish; a scavengerhttp://www.worldwid ewords.org/ weirdwords/ ww-mon1.htm
"Nagle's interests lie more with the trash collectors than with the trash, although the two intersect on the
subject of "mongo" -- sanitation lingo for "redeemed garbage" or the act of collecting it. (Nagle consulted a lexicographer, looking for help in tracking down the etymology, to no avail.)"
- Ben McGrath, New Yorker magazine from Nov. 13, 2006
(not to be confused with any other mongo, or mungo)