Picture someone taking hold of a plant and pulling until the whole thing comes up — stem, leaves, and the pale roots with soil still hanging off them. Nothing is left under the ground. That is the one picture behind every use of this word. Cutting leaves the roots, so the thing grows back; uprooting takes the part that made growing possible. Whatever the object is — a weed, a family, a habit — `uproot` says the hold on the ground has been broken.