locker UK /ˈlɒk.ə(ɹ)/US /ˈlɑ.kɚ/noun 8forms 1phrases 2 noun8 •a small metal box with a door and a key, where people keep their things at school, at work or at a gymThe student placed her books in her locker when she arrived at school. •A storage compartment on a ship, not necessarily one that can be locked. •A closet. •An online storage service for files.Then there are online service providers (OSPs), which might provide you with a message board, a blogging system, a video-hosting service, a file locker, an instant-messaging system, or an email box. — 2014 •A lockable cubicle.She was afraid to come out of the locker. •A locking differential. •(rare) One who locks something.The locker of the trapped chest must be careful, so as not to spring the trap. •(historical) A customs officer who guards a warehouse. formslockers Phrases with locker Davy Jones's lockerThe bottom of the sea, seen as a grave for sailors and the resting place of anything that goes overboard and is lost. locker room humorA type of humor involving jokes about crude and sexual topics.