firmament /fûrˈmə-mənt/

1. The solid sphere in which the stars were formerly thought to be fixed
2. The sky

• isonomy
• iso-octane
• isopach
• isopachs
• isopachyte
• isoperimeter
• isoperimeters
• isoperimetrical
• isoperimetries
• isoperimetry
• isopleth
• isopleths
• isopod
• Isopoda
• isopodan
• isopodous
• isopods
• isopolities
• isopolity
• isoprenaline
• isoprenalines
• isoprene
• isoprenes
• isopropyl
• isopropyls