prolusion /prə-, prō-looˈzhən or -lūˈ/

1. A preliminary performance, activity or display
2. An essay preparatory to a more solid treatise

proluˈsory /-sə-ri/ adjective

• oricalche
• oricalches
• orichalc
• orichalceous
• orichalcs
• oriel
• orielled
• oriels
• oriel-window
• oriencies
• oriency
• orient
• oriental
• Oriental
• oriental alabaster
• oriental alabasters
• oriental amethyst
• oriental emerald
• orientalise
• orientalised
• orientalises
• orientalising
• Orientalism
• Orientalist
• orientalities