1. (biology) a hypothetical force (not physical or chemical) once thought by Henri Bergson to cause the evolution and development of organisms
   - life force, vital force, vitality

Type of: force

• genus Serratia
• genus Serratula
• genus Sertularia
• genus Sesamum
• genus Sesbania
• genus Seseli
• genus Setaria
• genus Setophaga
• genus Shigella
• genus Shorea
• genus Shortia
• genus Sialia
• genus Sialis
• genus Sida
• genus Sidalcea
• genus Sideritis
• genus Sigmodon
• genus Silene
• genus Sillago
• genus Silphium
• genus Silurus
• genus Silvia
• genus Silybum
• genus Simarouba
• genus Simulium