1. [n]  the part of a tooth that is embedded in the jaw and serves as support
2. [n]  (linguistics) the form of a word after all affixes are removed; "thematic vowels are part of the stem"
3. [n]  a simple form inferred as the common basis from which related words in several languages can be derived by linguistic processes
4. [n]  the set of values that give a true statement when substituted into an equation
5. [n]  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"
6. [n]  someone from whom you are descended (but usually more remote that a grandparent)
7. [n]  the usually underground organ that lacks buds or leaves or nodes; absorbs water and mineral salts; usually it anchors the plant to the ground
8. [n]  a number that when multiplied by itself some number of times equals a given number
9. [adj]  arising from or going to the root; "a radical flaw in the plan"
10. [v]  take sides with; align oneself with; show strong sympathy for; "We all rooted for the home team"; "I'm pulling for the underdog"; "Are you siding with the defender of the title?"
11. [v]  take root; begin to grow; of plants
12. [v]  cause to take roots
13. [v]  become settled or established and stable in one's residence or life style; "He finally settled down"
14. [v]  dig with the snout; "the pig was rooting for truffles"
15. [v]  plant by the roots
16. [v]  come into existence, originate

Root
Root

more details ...

1. \ [So called after a Dr. Culver, who used it.] (Bot.)
   The root of a handsome erect herb ({Leptandra, syn. Veronica,
   Virginica}) common in most moist woods of North America, used
   as an active cathartic and emetic; also, the plant itself.
   

2. \Root\, v. i. [Cf. {Rout} to roar.]
   To shout for, or otherwise noisly applaud or encourage, a
   contestant, as in sports; hence, to wish earnestly for the
   success of some one or the happening of some event, with the
   superstitious notion that this action may have efficacy; --
   usually with for; as, the crowd rooted for the home team.
   [Slang or Cant, U. S.]
   

3. \Root\, v. i. [AS. wr[=o]tan; akin to wr[=o]t a snout,
   trunk, D. wroeten to root, G. r["u]ssel snout, trunk,
   proboscis, Icel. r[=o]ta to root, and perhaps to L. rodere to
   gnaw (E. rodent) or to E. root, n.]
   1. To turn up the earth with the snout, as swine.
   2. Hence, to seek for favor or advancement by low arts or
      groveling servility; to fawn servilely.
   

4. \Root\, v. t.
   To turn up or to dig out with the snout; as, the swine roots
   the earth.
   

5. \Root\, n. [Icel. r[=o]t (for vr[=o]t); akin to E. wort,
   and perhaps to root to turn up the earth. See {Wort}.]
   1. (Bot.)
      (a) The underground portion of a plant, whether a true
          root or a tuber, a bulb or rootstock, as in the
          potato, the onion, or the sweet flag.
      (b) The descending, and commonly branching, axis of a
          plant, increasing in length by growth at its extremity
          only, not divided into joints, leafless and without
          buds, and having for its offices to fix the plant in
          the earth, to supply it with moisture and soluble
          matters, and sometimes to serve as a reservoir of
          nutriment for future growth. A true root, however, may
          never reach the ground, but may be attached to a wall,
          etc., as in the ivy, or may hang loosely in the air,
          as in some epiphytic orchids.
   2. An edible or esculent root, especially of such plants as
      produce a single root, as the beet, carrot, etc.; as, the
      root crop.
   3. That which resembles a root in position or function, esp.
      as a source of nourishment or support; that from which
      anything proceeds as if by growth or development; as, the
      root of a tooth, a nail, a cancer, and the like.
      Specifically:
      (a) An ancestor or progenitor; and hence, an early race; a
          stem.
                They were the roots out of which sprang two
                distinct people.                  --Locke.
      (b) A primitive form of speech; one of the earliest terms
          employed in language; a word from which other words
          are formed; a radix, or radical.
      (c) The cause or occasion by which anything is brought
          about; the source. ``She herself . . . is root of
          bounty.'' --Chaucer.
                The love of money is a root of all kinds of
                evil.                             --1 Tim. vi.
                                                  10 (rev. Ver.)
      (d) (Math.) That factor of a quantity which when
          multiplied into itself will produce that quantity;
          thus, 3 is a root of 9, because 3 multiplied into
          itself produces 9; 3 is the cube root of 27.
      (e) (Mus.) The fundamental tone of any chord; the tone
          from whose harmonics, or overtones, a chord is
          composed. --Busby.
      (f) The lowest place, position, or part. ``Deep to the
          roots of hell.'' --Milton. ``The roots of the
          mountains.'' --Southey.
   4. (Astrol.) The time which to reckon in making calculations.
            When a root is of a birth yknowe [known]. --Chaucer.
   {A["e]rial roots}. (Bot.)
      (a) Small roots emitted from the stem of a plant in the
          open air, which, attaching themselves to the bark of
          trees, etc., serve to support the plant.
      (b) Large roots growing from the stem, etc., which descend
          and establish themselves in the soil. See Illust. of
          {Mangrove}.
   {Multiple primary root} (Bot.), a name given to the numerous
      roots emitted from the radicle in many plants, as the
      squash.
   {Primary root} (Bot.), the central, first-formed, main root,
      from which the rootlets are given off.
   {Root and branch}, every part; wholly; completely; as, to
      destroy an error root and branch.
   {Root-and-branch men}, radical reformers; -- a designation
      applied to the English Independents (1641). See Citation
      under {Radical}, n., 2.
   {Root barnacle} (Zo["o]l.), one of the Rhizocephala.
   {Root hair} (Bot.), one of the slender, hairlike fibers found
      on the surface of fresh roots. They are prolongations of
      the superficial cells of the root into minute tubes.
      --Gray.
   {Root leaf} (Bot.), a radical leaf. See {Radical}, a., 3
      (b) .
   {Root louse} (Zo["o]l.), any plant louse, or aphid, which
      lives on the roots of plants, as the Phylloxera of the
      grapevine. See {Phylloxera}.
   {Root of an equation} (Alg.), that value which, substituted
      for the unknown quantity in an equation, satisfies the
      equation.
   {Root of a nail}
      (Anat.), the part of a nail which is covered by the skin.
   {Root of a tooth} (Anat.), the part of a tooth contained in
      the socket and consisting of one or more fangs.
   {Secondary roots} (Bot.), roots emitted from any part of the
      plant above the radicle.
   {To strike root}, {To take root}, to send forth roots; to
      become fixed in the earth, etc., by a root; hence, in
      general, to become planted, fixed, or established; to
      increase and spread; as, an opinion takes root. ``The
      bended twigs take root.'' --Milton.
   

6. \Root\ (r[=oo]t), v. i. [imp. & p. p. {Rooted}; p. pr. &
   vb. n. {Rooting}.]
   1. To fix the root; to enter the earth, as roots; to take
      root and begin to grow.
            In deep grounds the weeds root deeper. --Mortimer.
   2. To be firmly fixed; to be established.
            If any irregularity chanced to intervene and to
            cause misappehensions, he gave them not leave to
            root and fasten by concealment.       --Bp. Fell.
   

7. \Root\, v. t.
   1. To plant and fix deeply in the earth, or as in the earth;
      to implant firmly; hence, to make deep or radical; to
      establish; -- used chiefly in the participle; as, rooted
      trees or forests; rooted dislike.
   2. To tear up by the root; to eradicate; to extirpate; --
      with up, out, or away. ``I will go root away the noisome
      weeds.'' --Shak.
            The Lord rooted them out of their land . . . and
            cast them into another land.          --Deut. xxix.
                                                  28.
   

1. The Unix superuser account (with user name "root" and user ID 0) that overrides file permissions. The term avatar is also used. By extension, the privileged system-maintenance login on any operating system.

See root mode, go root, wheel.

[Jargon File]

2. root directory.

3. root node.