octodecimo /ok-tō-desˈi-mō/

1. Having eighteen leaves to the sheet
2. Contracted 18mo, often read eighteenmo

A book with sheets so folded

• foundation degrees
• foundationer
• foundationers
• foundation garment
• foundation garments
• foundation hospital
• foundation hospitals
• foundation-muslin
• foundation-net
• foundations
• foundation school
• foundation schools
• foundation-stone
• foundation-stones
• foundation-stop
• foundation-stops
• foundation subject
• foundation subjects
• foundation trust
• foundation trusts
• founded
• founder
• foundered
• foundering
• founder member