"Farewell Rock" meaning in English

{
  "etymology_text": "Said to have been coined by ironstone miners who once worked the siderite deposits which stratigraphically overlie this rock unit. Digging beyond this bed would yield no further iron ore and so, on reaching it, they could bid a farewell to further riches.",
  "head_templates": [
    {
      "args": {
        "head": "Farewell Rock"
      },
      "expansion": "Farewell Rock",
      "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"
        }
      ],
      "glosses": [
        "A series of sandstones which lie at the boundary of the Coal Measures with the underlying Marros Group in South Wales."
      ],
      "id": "en-Farewell_Rock-en-name-NbN22lhX",
      "links": [
        [
          "sandstone",
          "sandstone"
        ],
        [
          "boundary",
          "boundary"
        ],
        [
          "Wales",
          "Wales"
        ]
      ],
      "wikipedia": [
        "Farewell Rock"
      ]
    }
  ],
  "word": "Farewell Rock"
}

{
  "etymology_text": "Said to have been coined by ironstone miners who once worked the siderite deposits which stratigraphically overlie this rock unit. Digging beyond this bed would yield no further iron ore and so, on reaching it, they could bid a farewell to further riches.",
  "head_templates": [
    {
      "args": {
        "head": "Farewell Rock"
      },
      "expansion": "Farewell Rock",
      "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 uncountable nouns"
      ],
      "glosses": [
        "A series of sandstones which lie at the boundary of the Coal Measures with the underlying Marros Group in South Wales."
      ],
      "links": [
        [
          "sandstone",
          "sandstone"
        ],
        [
          "boundary",
          "boundary"
        ],
        [
          "Wales",
          "Wales"
        ]
      ],
      "wikipedia": [
        "Farewell Rock"
      ]
    }
  ],
  "word": "Farewell Rock"
}