"Airy-0" meaning in English

{
  "etymology_text": "From Airy Crater, the larger crater this smaller crater is located within, and 0° of the prime meridian. Named after George Biddell Airy, a British astronomer who helped establish the Greenwich Meridian as the Prime Meridian on Earth.",
  "head_templates": [
    {
      "args": {},
      "expansion": "Airy-0",
      "name": "en-proper-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "derived": [
        {
          "alt": "AMT",
          "word": "Airy Mean Time"
        }
      ],
      "glosses": [
        "A crater on Mars, located within the larger Airy Crater, used as the determining landmark for the Martian prime meridian."
      ],
      "id": "en-Airy-0-en-name-v9PgX~d-",
      "links": [
        [
          "Airy Crater",
          "Airy Crater"
        ],
        [
          "prime meridian",
          "prime meridian"
        ]
      ],
      "wikipedia": [
        "en:Airy-0",
        "en:George Biddell Airy"
      ]
    }
  ],
  "word": "Airy-0"
}

{
  "derived": [
    {
      "alt": "AMT",
      "word": "Airy Mean Time"
    }
  ],
  "etymology_text": "From Airy Crater, the larger crater this smaller crater is located within, and 0° of the prime meridian. Named after George Biddell Airy, a British astronomer who helped establish the Greenwich Meridian as the Prime Meridian on Earth.",
  "head_templates": [
    {
      "args": {},
      "expansion": "Airy-0",
      "name": "en-proper-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English proper nouns",
        "English terms spelled with numbers",
        "English uncountable nouns"
      ],
      "glosses": [
        "A crater on Mars, located within the larger Airy Crater, used as the determining landmark for the Martian prime meridian."
      ],
      "links": [
        [
          "Airy Crater",
          "Airy Crater"
        ],
        [
          "prime meridian",
          "prime meridian"
        ]
      ],
      "wikipedia": [
        "en:Airy-0",
        "en:George Biddell Airy"
      ]
    }
  ],
  "word": "Airy-0"
}