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

See also: impossible

• inconsiderate
• inconsiderately
• inconsiderateness
• inconsideration
• inconsistency
• inconsistent
• inconsistently
• inconsolable
• inconsolably
• inconsonant
• inconspicuous
• inconspicuously
• inconspicuousness
• inconstancy
• inconstant
• inconstantly
• incontestability
• incontestable
• incontestably
• incontestible
• incontinence
• incontinency
• incontinent
• incontinently
• incontrovertibility