cave1/kev; keIv/n [C] a large natural hole in the side of a cliff or hill, or under the ground 山洞﹔洞穴﹐洞窟
cave2v cave in phr v 1 if the top or sides of something cave in, they fall down or inwards 坍落﹐坍塌﹔陷下: The roof caved in. 屋顶坍塌了。2 to stop opposing something 屈服﹐让步