English Reference
noun · adjective

interior

n. · adj.
US /ˌɪnˈtɪɹiɝ/ UK /ɪntˈiəɹɪɐ/ in·te·ri·or UK spelling interior's, interior's

  1. 01 B2 Upper Intermediate

    n.the inside part of a building, room, or vehicle.

    n.the internal part of a building, container, or other enclosed structure, often in relation to its design or decoration.

    Simple

    The interior of the old church was decorated with beautiful gold paintings.

    In context

    The architect focused on the interior of the cathedral, ensuring that the vaulted ceilings and stained glass created a sense of immense space.

    insideinner part
  2. 02 C1 Advanced Formal

    n.the part of a country that is far away from the coast or the borders.

    n.the central or inland regions of a country or continent, situated away from the maritime borders or frontiers.

    Simple

    It took the explorers months to travel from the coast into the country's interior.

    In context

    Economic development in the nation's interior has lagged behind the coastal cities due to the lack of reliable transport infrastructure.

  3. 03 C2 Proficiency Technical Math

    n.the set of all points inside a specific boundary.

    n.the set of all interior points of a given set; points that do not belong to the set's boundary.

    Simple

    In geometry class, we learned how to identify the interior of a circle.

    In context

    The theorem requires the function to be continuous on the closure of the set and differentiable on its interior.

  4. 04 B2 Upper Intermediate

    adj.located on the inside of something.

    adj.situated within or relating to the inside of something; internal.

    Simple

    The car has interior lights that turn on when you open the door.

    In context

    The interior walls of the spacecraft were lined with specialized insulation to protect the crew from extreme temperature fluctuations.

  5. 05 C1 Advanced Formal

    adj.describing a place that is far from the sea.

    adj.remote from the coast or frontier; situated in the inland part of a territory.

    Simple

    The interior parts of the continent are much hotter than the coastal areas.

    In context

    The interior tribes remained isolated from European trade for decades longer than those living along the Atlantic seaboard.

Usage interior ministry · interior minister

Why is it that the cities are so crowded while huge parts of the country's interior are empty?

The Local· 14 Aug 2026

Kim Weild’s production takes full advantage of this Spiegeltent-style venue’s mirrored interior, with the characters literally running rings around each other.

The Guardian· 14 Aug 2026
This entry
Level C1 · Advanced
Frequency Common
Updated