Related Clues:

• Eight, as a prefix
• Prefix for "eight"
• Hedron intro
• Two times tetra-
• Tetra- + tetra-
• 81-Across, as a prefix
• Prefix with "gon"
• Two-thirds of dodeca-
• Prefix before hedron or gon
• Rocky coast loses last of stratous area of cloud
• Deca- minus two
• Half of hexadeca-
• Hexa- plus two
• Bi- + hexa-
• Bi- x four