root1 S3 W2 [countable]
the part of a plant or tree that grows under the ground and gets water from the soil:
These plants produce a number of thin roots.
the main cause of a problem
cause of a problem
be/lie at the root of something (=be the cause of something)
Allergies are at the root of a lot of health problems.
The love of money is the root of all evil.
A competent mechanic should be able to get to the root of the problem (=find out the cause of a problem).
the root causes of crime
the origin or main part of something such as a custom, law, activity etc, from which other things have developed
a legal system with roots in English common law
Jazz has its roots in the folk songs of the southern states of the US.
be/lie at the root of something
the liberal economic policies which lie at the root of American power
your relation to a place because you were born there, or your family used to live there:
immigrants keeping in touch with their cultural roots
Alex Haley's story about his search for his roots became a bestseller.
if you put down roots somewhere, you start to feel that a place is your home and to have relationships with the people there:
Because of her husband's job, they'd moved too often to put down roots anywhere.
the part of a tooth, hair etc that connects it to the rest of your body:
She'd pulled some of Kelly's hair out by the roots.
if an idea, method, activity etc takes root, people begin to accept or believe it, or it begins to have an effect:
Economists believe that economic recovery will begin to take root next year.
if a plant takes root, it starts to grow where you have planted it
8 British English informal
to search for something by moving other things around
the basic part of a word which shows its main meaning, to which other parts can be added. For example, the word 'coldness' is formed from the root 'cold' and the suffix 'ness' [↪ stem]
a number that, when multiplied by itself a certain number of times, equals the number that you have:
2 is the fourth root of 16.
if you destroy or change something root and branch, you get rid of it or change it completely and permanently because it is bad:
a root and branch reform of the electoral system