zhì​xī​xìng​dú​jì

choking agent

  1. to suffocate
    to choke; to stifle; to struggle to breathe or stop breathing
  2. xìng affix
    [-ity]
    Suffix used after verbs or adjectives to form nouns expressing a state, quality, or scope, similar to English "-ity", "-ness", or "-ism".
  3. chemical weapon
    a chemical substance used in military operations to kill or injure people and livestock or destroy vegetation