root

How to sign: the place where something begins, where it springs into being
"the Italian beginning of the Renaissance"; "Jupiter was the origin of the radiation"; "Pittsburgh is the source of the Ohio River"; "communism's Russian root";

Similiar / Same: origin, source, rootage, beginning

Categories: point

Within this category: birthplace, derivation, fountainhead, headwaters, home, jumping-off place, point source, spring, trail head, wellhead

root

How to sign: someone from whom you are descended (but usually more remote than a grandparent)

Similiar / Same: ancestor, antecedent, ascendant, ascendent

Categories: relation, relative

Within this category: ancestress, forebear, forefather, foremother, progenitor

root

How to sign: (botany) the usually underground organ that lacks buds or leaves or nodes; absorbs water and mineral salts; usually it anchors the plant to the ground

Categories: plant organ

Within this category: adventitious root, briarroot, calamus, carrot, cassava, chicory, ginseng, horseradish, Hottentot bread, licorice root, mandrake root, orrisroot, parsnip, pneumatophore, prop root, radish, rootlet, salsify, sarsaparilla root, senega, taproot, taro

root

How to sign: the top directory in a file system, or, the Unix/Linux superuser account
"typically only administrators have a root level account";