Garage definition: 1. a building where a car is kept, built next to or as part of a house: 2. a place where cars are…. learn more.. A garage can be either a junk magnet or a storage haven. monica mangin from the weekender shares tips on how to achieve the latter with easy organization ide.... Finally was able to get back to the how to build a garage project during the process of pouring the concrete floor. i didn't make it while it was being poure....