"underlinement" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "underline",
        "3": "ment"
      },
      "expansion": "underline + -ment",
      "name": "suf"
    }
  ],
  "etymology_text": "From underline + -ment.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "underlinement (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms suffixed with -ment",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1967, Medical News Letter, volume 50, numbers 1-12, page 23:",
          "text": "The underlinement of the word acute is to emphasize the fact that all the data is based on acute effects and the long term or chronic effects, if any, are completely unknown.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Underlining."
      ],
      "id": "en-underlinement-en-noun-fShkmohr",
      "links": [
        [
          "Underlining",
          "underline"
        ]
      ],
      "tags": [
        "uncountable"
      ]
    }
  ],
  "word": "underlinement"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "underline",
        "3": "ment"
      },
      "expansion": "underline + -ment",
      "name": "suf"
    }
  ],
  "etymology_text": "From underline + -ment.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "underlinement (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English terms suffixed with -ment",
        "English terms with quotations",
        "English uncountable nouns",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "ref": "1967, Medical News Letter, volume 50, numbers 1-12, page 23:",
          "text": "The underlinement of the word acute is to emphasize the fact that all the data is based on acute effects and the long term or chronic effects, if any, are completely unknown.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Underlining."
      ],
      "links": [
        [
          "Underlining",
          "underline"
        ]
      ],
      "tags": [
        "uncountable"
      ]
    }
  ],
  "word": "underlinement"
}