he·li·cal /ˈhɛlɪkəl, ˈhi-/
  (a.)螺旋狀的
  he·li·cal /ˈhɛlɪkəl, ˈhɪlɪ-/ 形容詞
  螺旋狀的,螺旋的,螺旋狀
  helical
  螺旋形
  helical
  螺旋
  Hel·i·cal a.  Of or pertaining to, or in the form of, a helix; spiral; as, a helical staircase; a helical spring. -- Hel*i*cal*ly, adv.
  ◄ ►
  helical
       adj : in the shape of a coil [syn: coiling, spiral, spiraling,
              volute, voluted, whorled, turbinate]