1. interior angle the angle inside two adjacent sides of a polygon
  2. exterior angle the supplement of an interior angle of a polygon
  3. intermingle mix or become mixed
  4. interminable tiresomely long; seemingly without end
  5. internal angle the angle inside two adjacent sides of a polygon
  6. interpersonal occurring among or involving several people
  7. interchange cause to change places
  8. interior monologue a literary genre that presents a fictional character's sequence of thoughts in the form of a monologue
  9. interestingly in an interesting manner
  10. interchangeable permitting mutual substitution without loss of function
  11. interrobang punctuation mark (‽) expressing an exclamation as a question
  12. interfering intrusive in a meddling or offensive manner
  13. endearingly in an adorable manner
  14. wonderingly in a curious and questioning manner
  15. enduringly in an enduring manner
  16. enterprisingly in an enterprising manner
  17. anterior naris either one of the two external openings to the nasal cavity in the nose
  18. anteriorly in an anterior direction
  19. entertainingly in an entertaining manner
  20. acute triangle a triangle whose interior angles are all acute