1. Impossible to achieve
   - unachievable, unattainable, unrealizable, unrealisable [Brit]

See also: impossible

Encyclopedia: Undoable

• cowpea plant
• cowpen daisy
• Cowpens
• Cowper
• Cowper's gland
• cowpie
• cowpoke
• cowpox
• cowpuncher
• cowrie
• cowry
• cows
• cows' milk
• cowshed
• cowskin
• cowslip
• cowtown
• cox
• Cox's Orange Pippin
• Cox-1
• Cox-2
• Cox-2 inhibitor
• coxa
• coxcomb
• coxsackievirus