"undersound" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "under",
        "3": "sound"
      },
      "expansion": "under- + sound",
      "name": "prefix"
    }
  ],
  "etymology_text": "From under- + sound.",
  "forms": [
    {
      "form": "undersounds",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "undersound (plural undersounds)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with under-",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "2022, Robert Penn Warren, Wilderness: A Tale of the Civil War\nThe undersound filled the world, and his head, as he stared at the wheel. He thought of wheels turning, of people passing forever, in an endless procession, and the sound was always there, filling the air."
        }
      ],
      "glosses": [
        "An underlying or background sound."
      ],
      "id": "en-undersound-en-noun-KtKzxt9Q",
      "links": [
        [
          "underlying",
          "underlying"
        ],
        [
          "background",
          "background"
        ],
        [
          "sound",
          "sound"
        ]
      ]
    }
  ],
  "word": "undersound"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "under",
        "3": "sound"
      },
      "expansion": "under- + sound",
      "name": "prefix"
    }
  ],
  "etymology_text": "From under- + sound.",
  "forms": [
    {
      "form": "undersounds",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "undersound (plural undersounds)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English terms prefixed with under-",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "text": "2022, Robert Penn Warren, Wilderness: A Tale of the Civil War\nThe undersound filled the world, and his head, as he stared at the wheel. He thought of wheels turning, of people passing forever, in an endless procession, and the sound was always there, filling the air."
        }
      ],
      "glosses": [
        "An underlying or background sound."
      ],
      "links": [
        [
          "underlying",
          "underlying"
        ],
        [
          "background",
          "background"
        ],
        [
          "sound",
          "sound"
        ]
      ]
    }
  ],
  "word": "undersound"
}