English version


From Longman Dictionary of Contemporary English
Related topics: Construction
keystonekey‧stone /ˈkiːstəʊn $ -stoʊn/ noun  1 TBC[countable] the large central stone in an arch that keeps the other stones in position2 IMPORTANT[singular] formal the most important part of an idea, belief, or process that influences how it developskeystone of The keystone of any personal injury case is medical evidence.
Examples from the Corpus
keystone ofA high level of production has become a keystone of economic security.
Pictures of the day
Do you know what each of these is called?
Click on the pictures to check.