1. Impossible to answer
   "an unanswerable argument"

See also: incontestable, incontestible

• insufficiently
• insufflate
• insufflation
• insulant
• insular
• insularism
• insularity
• insulate
• insulating material
• insulating tape
• insulation
• insulator
• insulin
• insulin reaction
• insulin shock
• insulin shock therapy
• insulin shock treatment
• insulin-dependent diabetes mellitus
• insult
• insulting
• insultingly
• insuperable
• insuperably
• insupportable
• insurability