inner surface
- liningInterior fabric layer
- membraneThin tissue sheet
- wallVertical enclosing structure
- cavityEmpty space within
- interiorInside area or region
coating · hollow · concave · inside · layer · tissue · mucosa · enclosure · belly · womb · hull · rind · pith · core · chamber · vessel · sheath · cushion
spatial orientation
inner surfaceexterior
Outer portion
outside · outer layer · exterior wall · facade · outer wall