Cainozoic/kaynəʹzoh·ik/ adj and noun

• open prison
• open question
• open-reel
• open sandwich
• open season
• open secret
• open sesame
• open shop
• open slather
• Open University
• open up
• open verdict
• openwork
• opera
• operable
• opera buffa
• opera glasses
• opera hat
• opera house
• operand
• operant
• opera seria
• operate
• operatic
• operatics