octodecimo /ok-tō-desˈi-mō/

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

A book with sheets so folded

• insurgences
• insurgencies
• insurgency
• insurgent
• insurgents
• insuring
• insurmountability
• insurmountable
• insurmountableness
• insurmountably
• insurrection
• insurrectional
• insurrectionary
• insurrectionism
• insurrectionist
• insurrectionists
• insurrections
• insusceptibility
• insusceptible
• insusceptibly
• insusceptive
• insusceptively
• inswathe
• inswing
• inswinger