nonagenarian /nō-nə- or non-ə-ji-nāˈri-ən/

A person who is ninety years old, or between ninety and a hundred (also adjective)

• biquadratic
• biquadratic equation
• biquadratic equations
• biquadratic root
• biquadratic roots
• biquadratics
• biquintile
• biquintiles
• biracial
• biramous
• birch
• birchbark
• birchbarks
• birched
• birchen
• Bircher
• birches
• birch fly
• birching
• birchir
• birchirs
• birch rod
• birch rods
• bird
• bird-alane