noun 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.
noun A root vegetable.
noun The part of a tooth extending into the bone holding the tooth in place.
Root damage is a common problem of overbrushing.
noun The part of a hair under the skin that holds the hair in place.
The root is the only part of the hair that is alive.
noun The part of a hair near the skin that has not been dyed, permed, or otherwise treated.
He dyed his hair black last month, so the grey roots can be seen.
noun The primary source; origin.
The love of money is the root of all kinds of evil.
noun The section of a wing immediately adjacent to the fuselage.
noun The bottom of the thread of a threaded object.
The root diameter is the minor diameter of an external thread and the major diameter of an internal one.