1. Impossible to achieve
   "an unattainable goal"
   - unachievable, undoable, unrealizable, unrealisable [Brit]

See also: impossible, unattainableness

• unagitated
• unai
• unaided
• unaired
• unairworthy
• unalarming
• unalert
• unalienable
• unaligned
• unalike
• unalloyed
• unalterability
• unalterable
• unalterably
• unaltered
• unambiguity
• unambiguous
• unambiguously
• unambitious
• unambitiously
• unamended
• unamusing
• unanalysable
• unanalysed
• unanalyzable