root¹ / roōt; roŏt/ • n. 1. the part of a plant that attaches it to the ground or to a support, typically underground, conveying water and nourishment to the rest of the plant via numerous branches and fibers: cacti have deep and spreading roots a tree root. ∎  the persistent underground part of a plant, esp. when fleshy and enlarged and used as a vegetable, e.g., a turnip or carrot. ∎  any plant grown for such a root. ∎  the embedded part of a bodily organ or structure such as a hair, tooth, or nail: her hair was fairer at the roots. ∎  the part of a thing attaching it to a greater or more fundamental whole; the end or base: a little lever near the root of the barrel.2. the basic cause, source, or origin of something: love of money is the root of all evil jealousy was at the root of it | [as adj.] the root cause of the problem. ∎  the essential substance or nature of something: matters at the heart and root of existence. ∎  (roots) family, ethnic, or cultural origins, esp. as the reasons for one's long-standing emotional attachment to a place or community: it's always nice to return to my roots. ∎  [as adj.] (roots) denoting or relating to something, esp. music, from a particular ethnic or cultural origin, esp. a non-Western one: roots music. ∎  (in biblical use) a scion; a descendant: the root of David. ∎  Linguistics a morpheme, not necessarily surviving as a word in itself, from which words have been made by the addition of prefixes or suffixes or by other modification: many European words stem from this linguistic root | [as adj.] the root form of the word. ∎  Mus. the fundamental note of a chord.3. Math. a number or quantity that when multiplied by itself, typically a specified number of times, gives a specified number or quantity: find the cube root of the result. ∎ short for square root. ∎  a value of an unknown quantity satisfying a given equation: the roots of the equation differ by an integer. • v. [tr.] 1. cause (a plant or cutting) to grow roots: root your own cuttings from stock plants. ∎  [intr.] (of a plant or cutting) establish roots: large trees had rooted in the canal bank.2. (usu. be rooted) establish deeply and firmly: vegetarianism is rooted in Indian culture. ∎  (be rooted in) have as an origin or cause: the Latin dubitare is rooted in an Indo-European word. ∎  [tr.] [often as adj.] (rooted) cause (someone) to stand immobile through fear or amazement: she found herself rooted to the spot in disbelief. PHRASES: at root basically; fundamentally: it is a moral question at root.put down roots (of a plant) begin to draw nourishment from the soil through its roots. ∎  (of a person) begin to have a settled life in a particular place.root and branch used to express the thorough or radical nature of a process or operation: root and branch reform of personal taxation.strike at the root (or roots) of affect in a vital area with potentially destructive results: the proposals struck at the roots of community life.take root (of a plant) begin to grow and draw nourishment from the soil through its roots. ∎  become fixed or established: the idea had taken root in my mind.PHRASAL VERBS: root something out (also root something up) dig or pull up a plant by the roots. ∎  find and get rid of someone or something regarded as pernicious or dangerous: a campaign to root out corruption.DERIVATIVES: root·ed·ness n.root·let / -lət/ n.root·like / -ˌlīk/ adj.root·y adj.root² • v. [intr.] (of an animal) turn up the ground with its snout in search of food: stray dogs rooting around for bones and scraps. ∎  search unsystematically through an untidy mass or area; rummage: she was rooting through a pile of papers. ∎  [tr.] (root something out) find or extract something by rummaging: he managed to root out the cleaning kit.• n. [in sing.] an act of rooting: I have a root through the open drawers.PHRASAL VERBS: root for inf. support or hope for the success of (a person or group entering a contest or undertaking a challenge): the whole of this club is rooting for him.root someone on inf. cheer or spur someone on: his mother rooted him on enthusiastically from ringside.

ROOT.
1. Also sometimes radical. In traditional GRAMMAR and PHILOLOGY, the element, often monosyllabic, left after all affixes have been removed from a complex WORD: -ceive in receive, help in unhelpfully, act in reactivation. A root may or may not be a word, and may have several forms and meanings the further back it is traced in a language or languages. Compare BASE
.
2. Also ROOT-WORD. A word that is ancestral to a present-day word: the Latin verb decidere, the root of the English verb decide and the French verb décider. Compare ETYMON. The classical elements in the vocabulary of English have often been listed and discussed, especially in textbooks and dictionaries, as ‘LATIN and GREEK roots’, sometimes in the first sense given here, sometimes in the second sense, sometimes as a mix of the two.

In LINGUISTICS, a distinction is generally made not only between the two senses of root (above) but also between the terms root and base. The Latin nescius is the root or source of English nice, but is not a root in the philological sense. Rather, it consists of two elements, ne not, scius knowing. Its form cannot be detected anywhere ‘inside’ or ‘under’ present-day nice, which serves as a base for the formations nicety and niceness. Ne is a particle that also appears in neuter, and scius is made up of a linguistic root sci and an inflectional ending -us. Sci is present in the Latin scientia and its English derivative science; it is ancient, being the Latin ‘descendant’ of the Indo-European root *skei to cut, split. This ‘deep’ primoridial root also appears to underlie Old English scinu (Modern English shin), Old High German scina needle, Old Irish scian knife, Greek schizein to split, and Latin scindere to cut. See INDO-EUROPEAN ROOTS, ROOT-CREATION, WORD-FORMATION.

root
1. (in botany) The part of a vascular plant that grows beneath the soil surface in response to gravity and water. It anchors the plant in the soil and absorbs water and mineral salts. Unlike the stem, it never produces leaves, buds, or flowers and never contains chlorophyll. The radicle (embryonic root) may give rise either to a tap root system with a single main tap root from which lateral roots develop, or a fibrous root system, with many roots of equal size. The apical meristem at the root tip gives rise to a protective sheath, the root cap, and to the primary tissues of the root. The vascular tissues usually form a central core (see illustration). This distinguishes roots from stems, in which the vascular tissue often forms a ring. A short distance behind the root tip root hairs develop from the epidermis and greatly increase the surface area for absorption of water and minerals. Beyond this, lateral roots develop.

Roots may be modified in various ways. Some are swollen with food to survive the winter, as in the carrot. Certain plants, such as orchids, have absorptive aerial roots; others, such as ivy, have short clasping roots for climbing. The roots of leguminous plants, such as beans and peas, contain root nodules, which have an important role in nitrogen fixation. Other modifications include prop roots, stilt roots, and buttress roots, which support the plant; and pneumatophores.

2. (in dentistry) The portion of a tooth that is not covered with enamel and is embedded in a socket in the jawbone. Incisors, canines, and premolars have single roots; molars normally have several roots.

3. (in anatomy) The point of origin of a nerve in the central nervous system. There are two roots for every spinal nerve (see dorsal root; ventral root).

root (root) n.
1. (in neurology) a bundle of nerve fibres at its emergence from the spinal cord.

2. (in dentistry) the part of a tooth that is not covered by enamel and is normally attached to the alveolar bone by periodontal fibres. r. canal treatment the procedure of removing the remnants of the pulp of a tooth, cleaning and shaping the canal inside the tooth, and filling the root canal.

3. the origin of any structure, i.e. the point at which it diverges from another structure. Anatomical name: radix.

root put down roots begin to have a settled life in a particular place (literally, of a plant, begin to draw nourishment from the soil through its roots).
root and branch used to express the thorough or radical nature of a process or operation; originally with biblical allusion to Malachi 4:1 ‘the day cometh that shall burn them up…that it shall leave them neither root nor branch’.
the root of the matter the essential part of something; the expression comes originally from Job 19:28.
strike at the root affect in a vital area with potentially destructive results. A similar biblical metaphor for imminent destruction is found at Matthew 3:10.