It looks something like an elderberry. Do you have one in your yard or nearby? Does it look anything like something else in your yard or the neighbor's? Also somewhat black/rasp berry-ish.
Yes you could have a friend for life, it is one of those plants that grow from the smallest bit left.
You have to be persistent to remove it. You can grass the area and mow regularly for some years, cover with black polythene and leave covered for several years, hoe/hand weed on a weekly basis removing every bit you can see.
Do not dispose of in domestic compost as you will spread it. Send off site as green waste or drown in water butt for at least three months until a black, smelly, slimey mess.
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