"board foot" meaning in English

{
  "forms": [
    {
      "form": "board feet",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "board feet"
      },
      "expansion": "board foot (plural board feet)",
      "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": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Units of measure",
          "orig": "en:Units of measure",
          "parents": [
            "Metrology",
            "Quantity",
            "Applied sciences",
            "Mathematics",
            "Sciences",
            "Formal sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A board one square foot by one inch, about 2.36 liters."
      ],
      "id": "en-board_foot-en-noun-yVYLmGz9",
      "links": [
        [
          "square foot",
          "square foot"
        ],
        [
          "inch",
          "inch"
        ],
        [
          "liter",
          "liter"
        ]
      ],
      "related": [
        {
          "word": "linear foot"
        }
      ]
    }
  ],
  "word": "board foot"
}

{
  "forms": [
    {
      "form": "board feet",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "board feet"
      },
      "expansion": "board foot (plural board feet)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "linear foot"
    }
  ],
  "senses": [
    {
      "categories": [
        "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 board one square foot by one inch, about 2.36 liters."
      ],
      "links": [
        [
          "square foot",
          "square foot"
        ],
        [
          "inch",
          "inch"
        ],
        [
          "liter",
          "liter"
        ]
      ]
    }
  ],
  "word": "board foot"
}