1. Without advance preparation
   - ad lib, spontaneously, impromptu

Encyclopedia: Ad libitum

• sandwich
• sandwich board
• Sandwich Islands
• sandwich plate
• sandwichman
• sandwort
• sandy
• sandy mushroom
• sane
• sanely
• saneness
• sanfoin
• sang
• sang-froid
• sangam
• sangapenum
• sangaree
• Sangay
• Sanger
• Sango
• sangoma
• Sangraal
• sangria
• sanguification
• Sanguinaria