Definition of root noun from the Oxford Advanced American Dictionary



/rut; rʊt/

of plant

1 [countable] the part of a plant that grows under the ground and absorbs water and minerals that it sends to the rest of the plantdeep spreading rootsI pulled the plant up by (= including) the roots.Tree roots can cause damage to buildings.root crops/vegetables (= plants whose roots you can eat, such as carrots) see also grass roots, taproot

of hair/tooth/nail

2 [countable] the part of a hair, tooth, nail, or tongue that attaches it to the rest of the bodyhair that is blonde at the ends and dark at the roots

main cause of problem

3 [countable, usually singular] the main cause of something, such as a problem or difficult situationMoney, or love of money, is said to be the root of all evil.We have to get to the root of the problem.What lies at the root of his troubles is a sense of insecurity.What would you say was the root cause of the problem?


4 [countable, usually plural] the origin or basis of somethingFlamenco has its roots in Arabic music.

connection with place

5 roots [plural] the feelings or connections that you have with a place because you have lived there or your family came from thereI'm proud of my Italian roots.After 20 years in America, I still feel my roots are in England.

of word

6 [countable] (linguistics) the part of a word that has the main meaning and that its other forms are based on; a word that other words are formed from“Walk” is the root of “walks,” “walked,” “walking,” and “walker.”


7 [countable] a quantity that, when multiplied by itself a particular number of times, produces another quantity see also cube root, square root

put down roots

1 (of a plant) to develop roots2 to settle and live in one placeAfter ten years traveling the world, she felt it was time to put down roots somewhere.put down roots

take root

1 (of a plant) to develop roots2 (of an idea) to become accepted widelyFortunately, militarism failed to take root in Europe as a whole.take root
Usage noteUsage note: The Living Worldanimalsanimals mate/breed/reproduce/feed (on something)fish/amphibians swim/spawn(= lay eggs)birds fly/migrate/nest/singinsects crawl/fly/bite/stinginsects/bees/locusts swarmbees collect/gather nectar/pollenspiders spin/weave a websnakes/lizards shed their skinsbears/hedgehogs/frogs hibernateinsect larvae grow/develop/pupatean egg/a chick/a larva hatchesattract/find/choose a mateproduce/release eggs/spermlay/fertilize/incubate/hatch eggsinhabit a forest/a reef/the coastmark/enter/defend (a) territorystalk/hunt/capture/catch/kill preyplants and fungitrees/plants grow/bloom/blossom/flowera seed germinates/sproutsleaves/buds/roots/shoots appear/develop/formflower buds swell/opena fungus grows/spreads/colonizes somethingpollinate/fertilize a flower/plantproduce/release/spread/disperse pollen/seeds/sporesproduce/bear fruitdevelop/grow/form roots/shoots/leavesprovide/supply/absorb/extract/release nutrientsperform/increase/reduce photosynthesisbacteria and virusesbacteria/microbes/viruses grow/spread/multiplybacteria/microbes live/thrive in/on somethingbacteria/microbes/viruses evolve/colonize something/cause diseasebacteria break something down/convert something (into something)a virus enters/invades something/the bodya virus mutates/evolves/replicates (itself)be infected with/contaminated with/exposed to a new strain of a virus/drug-resistant bacteriacontain/carry/harbor bacteria/a viruskill/destroy/eliminate harmful/deadly bacteria