n. & v.
n. 1 a the part of a plant normally below the ground, attaching it to the earth and conveying nourishment to it from the soil. b (in pl.) such a part divided into branches or fibres. c the corresponding organ of an epiphyte; the part attaching ivy to its support. d the permanent underground stock of a plant. e any small plant with a root for transplanting. 2 a any plant, e.g. a turnip or carrot, with an edible root. b such a root. 3 (in pl.) the sources of or reasons for one's long-standing emotional attachment to a place, community, etc. 4 a the embedded part of a bodily organ or structure, e.g. hair, tooth, nail, etc. b the part of a thing attaching it to a greater or more fundamental whole. c (in pl.) the base of a mountain etc. 5 a the basic cause, source, or origin (love of money is the root of all evil; has its roots in the distant past). b (attrib.) (of an idea etc.) from which the rest originated. 6 the basis of something, its means of continuance or growth (has its root(s) in selfishness; has no root in the nature of things). 7 the essential substance or nature of something (get to the root of things). 8 Math. a a number or quantity that when multiplied by itself a usu. specified number of times gives a specified number or quantity (the cube root of eight is two). b a square root. c a value of an unknown quantity satisfying a given equation. 9 Philol. any ultimate unanalysable element of language; a basis, not necessarily surviving as a word in itself, on which words are made by the addition of prefixes or suffixes or by other modification. 10 Mus. the fundamental note of a chord. 11 Bibl. a scion, an offshoot (there shall be a root of Jesse). 12 Austral. & NZ coarse sl. a an act of sexual intercourse. b a (female) sexual partner.
v. 1 a intr. take root or grow roots. b tr. cause to do this (take care to root them firmly). 2 tr. a fix firmly; establish (fear rooted him to the spot). b (as rooted adj.) firmly established (her affection was deeply rooted; rooted objection to). 3 tr. (usu. foll. by out, up) drag or dig up by the roots. 4 tr. Austral. coarse sl. a have sexual intercourse with (a woman). b exhaust, frustrate. pull up by the roots 1 uproot. 2 eradicate, destroy. put down roots 1 begin to draw nourishment from the soil. 2 become settled or established. root and branch thorough(ly), radical(ly). root beer US an effervescent drink made from an extract of roots. root-mean-square Math. the square root of the arithmetic mean of the squares of a set of values. root out find and get rid of. root sign Math. = radical sign. strike at the root (or roots) of set about destroying. strike (or take) root 1 begin to grow and draw nourishment from the soil. 2 become fixed or established. rootage n. rootedness n. rootless adj. rootlet n. rootlike adj. rooty adj.
[ OE rot f. ON rót, rel. to WORT & L radix: see RADIX ]