"plain as Dunstable highway" meaning in All languages combined

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "plain as Dunstable highway (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "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 similes",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Synonym of plain as day."
      ],
      "id": "en-plain_as_Dunstable_highway-en-adj-Og67O6YJ",
      "links": [
        [
          "plain as day",
          "plain as day#English"
        ]
      ],
      "qualifier": "simile",
      "raw_glosses": [
        "(simile) Synonym of plain as day."
      ],
      "related": [
        {
          "word": "plain Dunstable"
        }
      ],
      "synonyms": [
        {
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "plain as day"
        }
      ],
      "tags": [
        "not-comparable"
      ]
    }
  ],
  "word": "plain as Dunstable highway"
}

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "plain as Dunstable highway (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "related": [
    {
      "word": "plain Dunstable"
    }
  ],
  "senses": [
    {
      "categories": [
        "English adjectives",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English similes",
        "English terms derived from toponyms",
        "English uncomparable adjectives",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "Synonym of plain as day."
      ],
      "links": [
        [
          "plain as day",
          "plain as day#English"
        ]
      ],
      "qualifier": "simile",
      "raw_glosses": [
        "(simile) Synonym of plain as day."
      ],
      "synonyms": [
        {
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "plain as day"
        }
      ],
      "tags": [
        "not-comparable"
      ]
    }
  ],
  "word": "plain as Dunstable highway"
}