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

• serrated
• serrated wrack
• Serratia
• Serratia marcescens
• serration
• Serratula
• Serratula tinctoria
• serratus
• serratus anterior
• serratus magnus
• serratus muscles
• serratus posterior
• serratus posterior inferior
• serratus posterior superior
• serried
• serrulate
• serry
• Sertoli cell
• Sertoli's cell
• sertraline
• Sertularia
• sertularian
• serum
• serum albumin
• serum disease