From Longman Dictionary of Contemporary Englishldoce_052_acorkcork1 /kɔːk $ kɔːrk/ noun 1 
[uncountable]TI the bark (=outer part) of a tree from southern Europe and North Africa, used to make things a cork bulletin board2 [countable]DFD a long round piece of cork or plastic which is put into the top of a bottle, especially a wine bottle, to keep liquid inside
[uncountable]TI the bark (=outer part) of a tree from southern Europe and North Africa, used to make things a cork bulletin board2 [countable]DFD a long round piece of cork or plastic which is put into the top of a bottle, especially a wine bottle, to keep liquid insideExamples from the Corpus
cork• Hebron is a cork in the bottle.• In the living room, a cork or two popped, releasing a stinging whistle of pressure into the air.• Announcement of the awards set champagne corks popping.• In 1939, leather was scarce so Magli introduced cork, fabric, velvet, fiber and wood to his shoes.• He was twiddling a piece of cork and sucking on his empty pipe.• Once you take the cork out, hopefully other things will start to flow.• Out with the corks of the wine, assuming you haven't done so already, and empty it into a saucepan.• Open the wine, lucky you've got a vacuum cork.corkcork2 verb [transitive] DFDSHUT/CLOSEto close a bottle by blocking the hole at the top tightly with a long round piece of cork or plastic OPP uncork→ See Verb tableCorkCork 1 the largest county in the Irish Republic2 the second largest city in the Irish RepublicOrigin cork1 (1200-1300) Probably from Arabic qurq, from Latin cortex; → CORTEX 