Entry 1 sense Webster, 1913 Helical /hĕl'-ĭk-əl/ · Hel·i·cal · IPA /ˈhɛl.ɪ.kəl/ 01 a. Of or pertaining to, or in the form of, a helix; spiral; as, a helical staircase; a helical spring. 1. Of or pertaining to, or in the form of, a helix; spiral; as, a helical staircase; a helical spring.