1. The apparent surface of the imaginary sphere on which celestial bodies appear to be projected
   - celestial sphere, sphere, empyrean, firmament, heavens, welkin

Type of: surface

• sulfurette
• sulfuretted
• sulfuric
• sulfuric acid
• sulfurised
• sulfurized
• sulfurous
• sulfury
• Sulidae
• sulindac
• sulk
• sulkily
• sulkiness
• sulky
• sulla
• sullage
• sullen
• sullenly
• sullenness
• Sullivan
• sully
• sulpha
• sulphadiazine
• sulphanilamide
• sulphanilic acid