"flag captain" meaning in English

{
  "forms": [
    {
      "form": "flag captains",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "flag captain (plural flag captains)",
      "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": "Entries with translation boxes",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Greek translations",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "The captain of a flagship in the Royal Navy."
      ],
      "id": "en-flag_captain-en-noun-k3smOw3t",
      "links": [
        [
          "captain",
          "captain"
        ],
        [
          "flagship",
          "flagship"
        ],
        [
          "Royal Navy",
          "Royal Navy"
        ]
      ],
      "translations": [
        {
          "code": "el",
          "lang": "Greek",
          "roman": "archiepistoléas",
          "sense": "flagship captain",
          "tags": [
            "masculine"
          ],
          "word": "αρχιεπιστολέας"
        }
      ]
    }
  ],
  "word": "flag captain"
}

{
  "forms": [
    {
      "form": "flag captains",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "flag captain (plural flag captains)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Entries with translation boxes",
        "Pages with 1 entry",
        "Pages with entries",
        "Terms with Greek translations"
      ],
      "glosses": [
        "The captain of a flagship in the Royal Navy."
      ],
      "links": [
        [
          "captain",
          "captain"
        ],
        [
          "flagship",
          "flagship"
        ],
        [
          "Royal Navy",
          "Royal Navy"
        ]
      ]
    }
  ],
  "translations": [
    {
      "code": "el",
      "lang": "Greek",
      "roman": "archiepistoléas",
      "sense": "flagship captain",
      "tags": [
        "masculine"
      ],
      "word": "αρχιεπιστολέας"
    }
  ],
  "word": "flag captain"
}