phrase[ plural ] the structures below the surface of the ground that support a building: 地基；房基 The foundations will have to be reinforced to prevent the house from sinking further into the ground.地基必须进行加固以防房屋继续下陷。 They made the discovery while digging foundations for new homes. The building's construction meant digging foundations to a depth of 49 feet. Contractors have already laid foundations for the new school. The explosion was so loud, it seemed to shake the foundations of the building we were in. See also