The Collaborative International Dictionary
Helispherical
Helispheric \Hel`i*spher"ic\, Helispherical \Hel`i*spher"ic*al\, a. [Helix + spheric, spherical.] Spiral.
Helispherical line (Math.). the rhomb line in navigation.
Wiktionary
helispherical
a. helispheric