English to English

noun (n)

• a blank gap or missing part(noun.artifact)

  Synonym:
  blank
  

  source: wordnet30
• an ornamental sunken panel in a ceiling or dome(noun.artifact)

  Synonym:
  caisson, coffer
  

  source: wordnet30
• A small opening; a small pit or depression; a small blank space; a gap or vacancy; a hiatus.(noun)

  source: webster1913