Something really Hip as in Good Excellent. Sammy Davis Jr.used it constantly in his stage act. Also a Sandwich in the Philly area. Wild Rock and Roll disc jockey TheMojoMan used it at every radio station he worked thru out the 60's 70's and 80's
Man,That DeLorean he bought is a Real Mammy Jammer. Or as TheMojoMan would intro "Land of a 1000 dances" by Wilson Pickett or "Born to be Wild" by Steppenwolf
Thats one bad mammyjammer.
One who has sexual relations with his own mother. A combination of mammy for mother and jammer to indicate sexual relations.
Used as a disparaging descriptor.
You degenerate mammy jammer.