From Longman Dictionary of Contemporary Englishlockerlock‧er /ˈlɒkə $ ˈlɑːkər/ ●○○ noun [countable] 1 
DSDCa small cupboard with a lock in a school, sports building, office etc, where you can leave clothes or possessions while you do something2 American EnglishDF a very cold room used for storing food in a restaurant or factory a meat locker
DSDCa small cupboard with a lock in a school, sports building, office etc, where you can leave clothes or possessions while you do something2 American EnglishDF a very cold room used for storing food in a restaurant or factory a meat lockerExamples from the Corpus
locker• Would a big eighth-grader shove me into a locker?• An attractive black dressed at the adjacent locker.• He took the steel key and inserted it into locker forty-seven.• In the daytime Mr Garner would rush off alone to repair a meat locker or an ice cream freezer.• All the contents of my locker had been tipped into a blanket.• Privately, some express worries about the effect of picking transsexuals on locker room morale.• Put any valuables out of sight, preferably in a strong locker with a secure padlock.• He spent the entire fourth quarter in the locker room. 