root

The part of a plant, generally underground, that anchors and supports the plant body, absorbs and stores water and nutrients, and in some plants is able to perform vegetative reproduction.

"This tree's roots can go as deep as twenty metres underground."

A root vegetable.

The part of a tooth extending into the bone holding the tooth in place.

"Root damage is a common problem of overbrushing."

To grow roots; to enter the earth, as roots; to take root and begin to grow.

"The cuttings are starting to root."

To prepare, oversee, or otherwise cause the rooting of cuttings

"We rooted some cuttings last summer."

To be firmly fixed; to be established.