(a.) of or pertaining to, or in the form of, a helix; spiral; as, a helical staircase; a helical spring.

O-shaped ambagious anfractuous backhanded circuitous circular cochlear cochleate corkscrew corkscrewy deviating deviative devious digressive discursive excursive helicoid indirect meandering oblique orbital out-of-the-way rotary round roundabout screw-shaped scrolled spiral spiroid turbinal turbinate verticillate volute voluted whorled