"linear metre" meaning in English

{
  "forms": [
    {
      "form": "linear metres",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "linear meter",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "linear metre (plural linear metres)",
      "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": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "langcode": "en",
          "name": "Units of measure",
          "orig": "en:Units of measure",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "A standard unit of length, symbol m, equal to one metre in length."
      ],
      "id": "en-linear_metre-en-noun-xCEs9X-z",
      "links": [
        [
          "standard",
          "standard"
        ],
        [
          "unit",
          "unit"
        ],
        [
          "length",
          "length"
        ],
        [
          "metre",
          "metre"
        ]
      ],
      "raw_glosses": [
        "(British spelling) A standard unit of length, symbol m, equal to one metre in length."
      ],
      "related": [
        {
          "word": "linear foot"
        }
      ],
      "tags": [
        "UK"
      ]
    }
  ],
  "word": "linear metre"
}

{
  "forms": [
    {
      "form": "linear metres",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "linear meter",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "linear metre (plural linear metres)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "linear foot"
    }
  ],
  "senses": [
    {
      "categories": [
        "British English forms",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Units of measure"
      ],
      "glosses": [
        "A standard unit of length, symbol m, equal to one metre in length."
      ],
      "links": [
        [
          "standard",
          "standard"
        ],
        [
          "unit",
          "unit"
        ],
        [
          "length",
          "length"
        ],
        [
          "metre",
          "metre"
        ]
      ],
      "raw_glosses": [
        "(British spelling) A standard unit of length, symbol m, equal to one metre in length."
      ],
      "tags": [
        "UK"
      ]
    }
  ],
  "word": "linear metre"
}