柯林斯詞典double bond 1. N a type of chemical bond consisting of two covalent bonds linking two atoms in a molecule 雙鍵 返回 double bond劍橋詞典a chemical bond in which a molecule has two shared pairs of electrons 雙鍵（兩個原子間以兩對共享電子構成的化學鍵） 返回 double bond