defoliant [ˌdi:ˈfoʊliənt]

例句:

• The crash had spilled a noxious defoliant into the planet's ecology, ravaging the native flora.
  这次坠毁将一种有害的落叶剂洒入星球的生态系统中, 破坏着当地的植物群.
  
• Defoliant: Chemical dust or spray applied to plants to cause their leaves to drop off prematurely.
  落叶剂: 落叶剂是一种化学粉剂或喷洒剂,施于植物以使树叶提早掉落.
  
• Agent Orange was a dioxin-laden defoliant that was sprayed over jungles to strip the Viet Cong of cover.
  来自MSN