Longman Dictionary of Contemporary English - base

~1 v to establish or use somewhere as the main place for your business or work  (a Denver-based law firm) base sth on/upon sth phr v T often passive to use particular information or facts as a point from which to develop an idea, plan etc  (The film is based on a novel by Sinclair Lewis.) ~2 n 1 »LOWEST PART« C usually singular the lowest part of something, or the surface at the bottom of something + of  (There was a chip in the base of the glass. | the base of a triangle | Waves crashed and pounded at the base of the cliff.) 2 »KNOWLEDGE/IDEAS« the most important part of something from which new ideas develop  (India has a good scientific research base. | This provides a good base for the development of new techniques.) 3 »COMPANY/ORGANIZATION« the main place from which a group, company, or organization controls its activities  (Cuba was seen as a base for Communist activity throughout Latin America. | Report back to base as soon as you see anything.) 4 »MILITARY« a place where people in a military organization live and work  (a naval base) 5 »PEOPLE/GROUPS« C usually singular the people, money, groups etc from which a lot of support or power comes  (an attempt to strengthen the city's economic base | tax/customer base (=all the people who pay tax or buy goods in a particular place))  (A reputation for excellent service will expand our customer base. | manufacturing base (=all the factories, companies etc that produce goods in a country))  (The country's manufacturing base has shrunk by 20% during the recession.)  (- see also power base) 6 »SUBSTANCE/MIXTURE« the main part of a substance to which something else is later added  (paint with an oil base) 7 »BODY/PLANT« C usually singular the point where part of your body or part of a plant joins with the rest  (She had a dull ache at the base of her neck.) 8 »SPORT« one of the four places that a player must touch in order to get a point in games such as baseball 9 be off base AmE informal to be completely wrong  (His estimate for painting the kitchen seems way off base.) 10 »CHEMISTRY« technical a chemical substance that combines with an acid to form a salt1 (3) 11 »NUMBERS« C usually singular technical the number in relation to which a number system or mathematical table is built up 12 touch base (with sb) to telephone someone who you live or work with, or make a short visit, while you are spending time somewhere else  (- see also cover (all) the bases cover1 (13)) ~3 adj literary not having good moral principles  (base passions)  (- see also base metal)