Dictionary.com
Thesaurus.com

plagiohedral

American  
[pley-jee-uh-hee-druhl] / ˌpleɪ dʒi əˈhi drəl /
Also plagihedral

adjective

  1. (of a crystal) having faces arranged obliquely in a helix.


Etymology

Origin of plagiohedral

plagio- + -hedral