When you implant something, you place or embed it solidly: you might implant marbles in the damp concrete of a newly poured sidewalk, for example.
There are a couple of different ways to implant something — the first is to physically fix an item deeply, the way you might implant a croquet wicket in the ground. A more figurative way to implant is to settle an idea into someone's mind. You could accidentally implant a fear of highway driving in your younger brother's mind, for example, by telling him stories of traffic accidents. Implant comes from the French word implanter, "to insert."