Mama jama, mamma jamma, mammer jammer, mamma-jamma, and other similar spellings are all ameliorated profanities in the English language, substituting the word "motherfucker" in a way that, if repeated by small children or allowed to slip in sensitive social environments, will not induce outrage in the more conservative adults nearby.
Popular use of this minced oath began approximately with Don and Dewey, in the song Mammer Jammer, which unambiguously indicates that "mammy jamming" is an act not to be spoken of in polite company.
The 1982 R&B single "She's a Bad Mama Jama (She's Built, She's Stacked)" by Carl Carlton demonstrates that over the term's evolution since the early 1960s, the euphemism - along with the obscenity it replaces - has gained a positive connotation, as long as "bad" is placed before it in speech. A "bad motherfucker" is typically understood to be a formidable and impressive individual with a low bullshit tolerance and a great deal of competence at handling himself. Likewise, a "bad mama jama" has these features, on top of a certain affable and attractive quality implied by using the ameliorated word: a mama jama is less serious than a motherfucker, but remains a similar sort of creature. One might surmise that a bad mama jama is also built like a brick shithouse, possessing aesthetically favourable body proportions.
More recently, in the Key & Peele comedy sketch "Prepared for Terries," the term is used to describe terrorists on airplanes, without the addition of "bad" to make it imply the term is a compliment.
Iron Noder 2017, 21/30