单词：na 

名词

• 
  [1.n.na] (同义词:[sodium( n. [化] 钠 )]  [Na( [域] Namibia , 纳米比亚 )]  [atomic_number_11]  )
• 
  注释列句：a silvery soft waxy metallic element of the alkali metal group; occurs abundantly in natural compounds (especially in salt water); burns with a yellow flame and reacts violently in water; occurs in sea water and in the mineral halite (rock salt)
• 上位词 -> [metallic_element]  [chemical_element]  [substance( n. 物质, 实质, 主旨 )]  [matter( n. 事件, 问题, 物质, 内容, 实质, 原因, (印刷或书写的)文件, (文章或讲话等的)素材 vi. 有关系, 要紧 )]  [physical_entity]  [entity( n. 实体 )] 
• 基本总称 -> [seawater( n. 海水 )]  [halite( n. [化]岩盐 )] 
  所有总称 -> [seawater( n. 海水 )]  [halite( n. [化]岩盐 )]