I've blogged on this several times. The word 'hoodoo' is not African. It's Scott-Irish. If you go to google and then click on news and type in 'hoodoo' you will get all kinds of European uses of the word which has nothing to do with the Southern, magical-spiritual tradition of conjure work.
The word hoodoo means "cursed, unlucky". In the original use of the word if something or someone is a hoodoo then than person is believed to be cursed or unlucky. Anything can be a hoodoo. So if Sally down the block is rumored to be a hoodoo that did not originally mean that she was a conjure worker. Instead, it meant that she had the reputation of being cursed and that people avoid her for that reason. You don't want to board a ship, plane, or train with someone is known to be a hoodoo for fear of having a wreck for example.
The word hoodoo first popped up in the U.S. in the late 1800s. Now some authors online will claim that the word hoodoo comes from the term, "Palo Judio", as pronounced by Spanish speaking people (hoo-dee-o), which evolved into the modern word 'hoodoo'. The problem with this theory is that if this was the case then the word would have been used far before the late 1800s. This also leads doubt that the word is African in origin as it also would have been used far longer. We know the slaves were practicing this tradition since about day one of their arrival. What we do know is that the word hoodoo popped up around the same time as a wave of Irish immigrants who fled to the U.S. due to a potato famine. These people had a rich tradition of folklore and folkmagic. They brought Halloween to the U.S. The Scott-Irish people, and Scott-Irish is slang for people of Scottish, Irish, and English heritage, had a huge impact on the tradition. For example, the following words/terms are from the Scott-Irish people and are not African or completely African.
-Black Man At The Crossroads (Why would a black person say "black man at the crossroads". This phrase was used heavily by the Scott-Irish and in their folklore "the Black Man", the man dressed in black, is the devil.) It is possible that the slaves retained their belief in the crossroads spirit. Or it could be that "the Black Man" is entirely Scott-Irish in origin. A mixture of the two is also possible.
-"Haint" - The word "haint", meaning spirit, ghost, is Scott-Irish. You will read black person after black person use the term "haint" in older written accounts of the tradition. There is a reason they are using haint and not "ghost" (Germaan = "geist", as in "poltergeist")
-Crossroads - Like Africans, the Scott-Irish had a rich tradition of the importance of the crossroads in their folklore and folkmagic.
-Black Cats - The superstition of the black cats is European in origin. It has been somewhat twisted and give new meaning in the tradition.
-Jack-O'-Lantern - Like with the word "haint", in written accounts black people are using the term, "Jack-O'-Lantern" far more frequently than similar terms such as "Fox Fire" or "Will-O'-The Wisp". All three terms are of European origin and not African but the term "Jack-O'-Lantern" comes specifically from the Irish. Before it was identified with the pumpkin the Jack-O'-Lanterns was the mysterious balls of light one may encounter on dark nights near swampy areas. They were believed to be the work of spirits and were considered dangerous. The term "Jack-O'-Lantern" specifically refers to the Irish legend of "Stingy Jack" who was too bad for heaven and too good for hell. When he tricked the devil he was made to wander the earth until Doomsday carrying a lump of hell-coal in a hollowed out turnip as his only light.
The reason why the Scott-Irish played such a greater role in the formation of conjure work is because the wave of immigrants in the late 1800s were dirt poor and lived and worked side-by-side with black people. They two cultures began to mix and share stories and tricks.
So somewhere along the way the Scott-Irish term of 'hoodoo', as a cursed or unlucky object or person, was taken up as a name for the tradition and for practitioners of that tradition. However, older folks still retain the older meaning of the word. For many older folks the term hoodoo is a synonym for 'witchcraft'. Even if an older person is a worker or practitioner they will often deny they that they practice 'hoodoo'.