1. Impossible to achieve
   - unachievable, unattainable, undoable, unrealizable

See also: impossible

• terrine
• territorial
• Territorial Army
• territorial division
• territorial dominion
• territorial reserve
• territorial waters
• territorialisation
• territorialise
• territoriality
• territorialization
• territorialize
• territorially
• territory
• terror
• terror-stricken
• terror-struck
• terrorisation
• terrorise
• terrorism
• terrorist
• terrorist act
• terrorist attack
• terrorist cell
• terrorist group