From Longman Dictionary of Contemporary Englishcoolercool‧er /ˈkuːlə $ -ər/ ●●○ noun [countable] 1 
DFUa container in which something, especially drinks, is cooled or kept cold Mike went to fetch a bottle of wine from the cooler.2 American EnglishDFU a coolbox3 American EnglishDHTB a machine that provides air conditioning4 → the cooler
DFUa container in which something, especially drinks, is cooled or kept cold Mike went to fetch a bottle of wine from the cooler.2 American EnglishDFU a coolbox3 American EnglishDHTB a machine that provides air conditioning4 → the coolerExamples from the Corpus
cooler• a cooler full of beer and soft drinks• Special aquarium coolers are available and beer coolers can be adopted.• But as Michele had prophesied, it was already getting cooler, and Luce was glad of her light coat.• Pack a well-insulated cooler with perishable foods the day of the picnic.• And looking a little cooler, Emma Jesson from the weather department.• Marie slipped Omar a dollar to buy ice cream from a boy with a silver cooler strapped to his chest.• But, if the cooler conditions persist, and Melbourne is notorious for its fickle weather, it will favour Lapentti.• The heat in the air moves to the cooler liquid.• Paco and I made Bloody Marys last night in this cooler. 