In Britain, one traditionally associates double-barrelled surnames with the aristocracy or landed gentry, originally as a way of keeping going a surname that would otherwise have died out, due to lack of male children to carry it on. However it is my impression that there is a significant incidence of double-barrelled surnames among British black people, of Caribbean (as opposed to African) extraction. Here is one example in the news at the moment: http://www.bbc.co.uk/sport/commonwealth-games/43735185 I have not been able to find an explanation of the origin of this practice. I wonder if perhaps it is from Spanish custom (in which children take the surnames of both parents' families), perhaps from the way slaves were named, or perhaps from something else entirely. Does anyone have an explanation, preferably with links to some further reading?
It would not be the only social custom of the aristocracy or landed gentry that the black underclass adopted for some reason, as soon as they were out from under slavery. https://en.wikipedia.org/wiki/Cotillion https://www.pinterest.com/enneanderson/vintage-black-debutantes-cotillions/
But not to anyone attending to the meaning of the word as posted from the dictionary above (and not so labeled by anyone afaik) - any more than the double surname would be explained by such carelessness and disrespect (or is labeled as such). Some of the explanations that serve for cultural appropriation will not serve for this, in other words. You sought explanation, and will be looking elsewhere.
The common human pattern of lower classes picking up the signifiers of high status as they lived under it doesn't work for you?
