Re the supposed racial origins of the word: there was a standard phrase which you will find in line 2 of Johnny Come Down To Hilo in DT - "From American Ballads and Folk Songs, Lomax: Recorded by Forebitter, also Oscar Brand"

and it is no use pretending at this time of day that there wasn't. English MP Sir Gerald Nabarro got much criticised for using it on BBC radio in 1963, "remarks which were excised from a repeat of the programme [Any Questions] the following week", tho he claimed he had meant it in a complimentary sense! Read all about it in his Wikipedia entry.

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