"finback" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "fin",
        "3": "back"
      },
      "expansion": "fin + back",
      "name": "compound"
    }
  ],
  "etymology_text": "From fin + back.",
  "forms": [
    {
      "form": "finbacks",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "finback (plural finbacks)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "langcode": "en",
          "name": "Whales",
          "orig": "en:Whales",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "A large baleen whale, Balaenoptera physalus, that has a ridge on its back; the fin whale."
      ],
      "id": "en-finback-en-noun-ZZKyIATl",
      "links": [
        [
          "baleen whale",
          "baleen whale"
        ],
        [
          "Balaenoptera physalus",
          "Balaenoptera physalus#Translingual"
        ],
        [
          "ridge",
          "ridge"
        ],
        [
          "fin whale",
          "fin whale"
        ]
      ],
      "synonyms": [
        {
          "word": "finner"
        }
      ]
    }
  ],
  "word": "finback"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "fin",
        "3": "back"
      },
      "expansion": "fin + back",
      "name": "compound"
    }
  ],
  "etymology_text": "From fin + back.",
  "forms": [
    {
      "form": "finbacks",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "finback (plural finbacks)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English compound terms",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Whales"
      ],
      "glosses": [
        "A large baleen whale, Balaenoptera physalus, that has a ridge on its back; the fin whale."
      ],
      "links": [
        [
          "baleen whale",
          "baleen whale"
        ],
        [
          "Balaenoptera physalus",
          "Balaenoptera physalus#Translingual"
        ],
        [
          "ridge",
          "ridge"
        ],
        [
          "fin whale",
          "fin whale"
        ]
      ]
    }
  ],
  "synonyms": [
    {
      "word": "finner"
    }
  ],
  "word": "finback"
}