← BackshareGuesshelicoidal/ˌhɛlɪˈkɔɪdəl/adjectiveShaped like a spiral or helix; twisted.The helicoidal ramp in the parking garage was easy to drive up.The architect used a helicoidal design for the tower's outer wall.The helicoidal pattern of the fern's leaves caught my eye.SynonymscoiledhelicalspiralAntonymsstraight