"rarer" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "comparative adjective"
      },
      "expansion": "rarer",
      "name": "head"
    }
  ],
  "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": "Pages with 2 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "_dis": "37 35 9 9 9",
          "kind": "other",
          "name": "Pages with 2 entries",
          "parents": [],
          "source": "w+disamb"
        }
      ],
      "examples": [
        {
          "ref": "1951 October, “Notes and News: The Harmonium at Troutbeck”, in Railway Magazine, page 709:",
          "text": "Unfortunately, even in the palmiest days of the old Cockermouth, Keswick & Penrith Railway Company, passengers were few and far between at Troutbeck, and since the advent of the motor bus road services they are rarer than ever, and never likely to increase.",
          "type": "quote"
        }
      ],
      "form_of": [
        {
          "extra": "more rare",
          "word": "rare"
        }
      ],
      "glosses": [
        "comparative form of rare: more rare"
      ],
      "id": "en-rarer-en-adj-8o8Y5BhJ",
      "links": [
        [
          "rare",
          "rare#English"
        ]
      ],
      "tags": [
        "comparative",
        "form-of"
      ]
    }
  ],
  "word": "rarer"
}

{
  "categories": [
    "Pages with 2 entries",
    "Pages with entries"
  ],
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "comparative adjective"
      },
      "expansion": "rarer",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English comparative adjectives",
        "English entries with incorrect language header",
        "English non-lemma forms",
        "English terms with quotations",
        "Pages with 2 entries",
        "Pages with entries"
      ],
      "examples": [
        {
          "ref": "1951 October, “Notes and News: The Harmonium at Troutbeck”, in Railway Magazine, page 709:",
          "text": "Unfortunately, even in the palmiest days of the old Cockermouth, Keswick & Penrith Railway Company, passengers were few and far between at Troutbeck, and since the advent of the motor bus road services they are rarer than ever, and never likely to increase.",
          "type": "quote"
        }
      ],
      "form_of": [
        {
          "extra": "more rare",
          "word": "rare"
        }
      ],
      "glosses": [
        "comparative form of rare: more rare"
      ],
      "links": [
        [
          "rare",
          "rare#English"
        ]
      ],
      "tags": [
        "comparative",
        "form-of"
      ]
    }
  ],
  "word": "rarer"
}