垂线 (垂線) chuíxiàn
          
              chuíxiàn 
              
              noun 
              perpendicular line; vertical line 
              Domain: Modern Chinese 现代汉语
              
                , Subdomain: Mathematics 
              
              
                , Concept:  
              
              
              
                Notes: (CC-CEDICT '垂線')