Related Clues:

• Prefix for eight
• Eight, for starters
• Hepta- plus one
• Penta- plus three
• Numeric prefix
• Bi- times four
• Beginning of eight words?
• Prefix for ''ten''
• Penta- doubled
• Word form for ''eight''
• Twice tetra
• Nona- plus one
• Pod opening
• Prefix for -gon
• Twice penta-