roundworm [ˈraʊndwɜ:rm]

例句:

• The downside to this is that the birds may ingest the eggs of roundworm, which may block their windpipes.
  来自BBC
• Ascariasis is infection with the parasitic roundworm Ascaris lumbricoides.
  蛔虫病是由一种叫蛔虫的寄生虫引起的感染.
  
• That's only three times more than a fruit fly and twice as many as a roundworm.
  这个数字只是果蝇的3倍、线虫的2倍.