trackball [ˈtrækˌbɔl]

例句:

• Move your mouse or trackball in the straightest line possible.
  尽可能在最直的线上移动您的鼠标或轨迹球.
  
• Fixed auto brightness, hardware key lights and trackball light notifications.
  固定自动亮度, 硬件锁灯和轨迹球通知.
  
• A mouse takes much more room than a trackball.
  鼠标要比轨迹球占地方的多.
  
• Williamson is also credited with 'trackball'.
  来自BBC
• Non-touchscreen phones that use a trackball or buttons to navigate will present a more compact page.
  来自BBC