Instead of newer genres, it's more an older, rough, tough 'biker' usage... for someone to be wary of, aware of, watch out for, cognizant of... used informatively, often as a warning.
sarcasticly - similar to 'a real nice guy', 'a real sweetheart'
"You'd better watch out for that one, he's a real mother... "
mo-fo
by realisms June 4, 2010
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An individual who can always see through the bullshit. Particular people who don't like sugar coating or pussyfooting and/or beating around the bush. A person who takes their own inventory before taking anyone else's.

Male RMF: a proud solid man, one whom has the most sensitive bullshitometer.

Female RMF: a bitch who is down to go ham on yo girl when she acting a hoe round her mans.
Remember how that dude Barret always was genuine and his own brand, that dude was a RMF (Real Mother Fucker)
by Beezy Whyte May 26, 2022
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Genetic real son and mother do piv. son then becomes a real mother fucker.
Real as it can be, never actually seen a RMF (Real Mother Fucker); just like they say, inscrutable, volatile, a bit tricky to deal with.
by sweetmouthnipple69 August 22, 2018
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