I have researched the word. I've also researched the topic. That's how I know the dictionary meaning that you posted is, to say the least, incomplete. A number of the arts listed in the OT have to do with communing with the dead. And they are all forbidden. How can you be christian and not know the law? How is it that a Jew knows these things and you don't? Where's Angelo.
I will again ask: would you avoid buying a linen-wool blend jacket? And add: for that matter, do you make sure the meat you buy at the supermarket wasn't strangled?--that's part the Apostles kept. Do you seriously believe that a widower who stops by his wife's grave and sits a while and addresses his wife in imaginary conversation for his comfort is a necromancer? If you have mold or mildew, do you call a priest and have him scrape the wall it's on, then come back later and check, and tear down your house if it came back? Do you not eat pork or lobster?
I suspect you are not so zealous for the Old Covenant Law as you let on, and have just picked passage from it you can twist into a justification for your preconceived idea that the historic Christian practice of asking the intercessions of the saints in Christ is wrong.