"book rate" meaning in All languages combined

{
  "forms": [
    {
      "form": "book rates",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "book rate (plural book rates)",
      "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"
        }
      ],
      "glosses": [
        "The rate charged for mailing printed matter by book post."
      ],
      "id": "en-book_rate-en-noun-6Cdh4jvx",
      "links": [
        [
          "rate",
          "rate"
        ],
        [
          "charged",
          "charged"
        ],
        [
          "mail",
          "mail"
        ],
        [
          "printed matter",
          "printed matter"
        ],
        [
          "book post",
          "book post"
        ]
      ],
      "raw_glosses": [
        "(dated, obsolete) The rate charged for mailing printed matter by book post."
      ],
      "tags": [
        "dated",
        "obsolete"
      ]
    }
  ],
  "word": "book rate"
}

{
  "forms": [
    {
      "form": "book rates",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "book rate (plural book rates)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English dated terms",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with obsolete senses",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "The rate charged for mailing printed matter by book post."
      ],
      "links": [
        [
          "rate",
          "rate"
        ],
        [
          "charged",
          "charged"
        ],
        [
          "mail",
          "mail"
        ],
        [
          "printed matter",
          "printed matter"
        ],
        [
          "book post",
          "book post"
        ]
      ],
      "raw_glosses": [
        "(dated, obsolete) The rate charged for mailing printed matter by book post."
      ],
      "tags": [
        "dated",
        "obsolete"
      ]
    }
  ],
  "word": "book rate"
}