octodecimo /ok-tō-desˈi-mō/

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

A book with sheets so folded

• amphora
• amphorae
• amphoras
• amphoric
• amphoteric
• ampicillin
• ampicillins
• ample
• ampleness
• amplenesses
• ampler
• amplest
• amplexicaul
• amplexus
• ampliation
• ampliations
• ampliative
• amplification
• amplifications
• amplified
• amplifier
• amplifiers
• amplifies
• amplify
• amplifying