Root1  —n. 1 a part of a plant normally below the ground, conveying nourishment from the soil. B (in pl.) Branches or fibres of this. C small plant with a root for transplanting. 2 a plant with an edible root. B such a root. 3 (in pl.) Emotional attachment or family ties to a place or community. 4 a embedded part of a hair, tooth, nail, etc. B part of a thing attaching it to a greater whole. 5 (often attrib.) Basic cause, source, nature, or origin (root of all evil; roots in the distant past; root cause; the root of things). 6 a number that when multiplied by itself a usu. Specified number of times gives a specified number or quantity (cube root of eight is two). B square root. C value of an unknown quantity satisfying a given equation. 7 core of a word, without prefixes, suffixes, etc. —v. 1 (cause to) take root; grow roots (root them firmly). 2 (esp. As rooted adj.) Fix firmly; establish (rooted objection to; reaction rooted in fear). 3 (usu. Foll.