Root

1. The usually underground portion of a plant that lacks buds, leaves, or nodes and serves as support, draws minerals and water from the surrounding soil, and sometimes stores food. Too much constant water will damage the root of a tree and it may die.
2. An essential part or element; the basic core. We need to get to the root of the problem.
3. The condition of being settled and of belonging. Our roots in this town go back a long way.