"main-truck" meaning in English

{
  "etymology_text": "\"Main\" refers to the mainmast, whereas a truck on another mast may be called (on the mizzenmast, for example) \"mizzen-truck\".",
  "forms": [
    {
      "form": "main-trucks",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "main-truck (plural main-trucks)",
      "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": "topical",
          "langcode": "en",
          "name": "Nautical",
          "orig": "en:Nautical",
          "parents": [
            "Transport",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "On a wooden mast, a circular disc (or sometimes a rectangle) of wood near or at the top of the mast, usually with holes or sheaves to reeve signal halyards; also a temporary or emergency place for a lookout."
      ],
      "id": "en-main-truck-en-noun-wA18Jc4h",
      "links": [
        [
          "nautical",
          "nautical"
        ],
        [
          "mast",
          "mast"
        ],
        [
          "sheaves",
          "sheaves"
        ],
        [
          "reeve",
          "reeve"
        ],
        [
          "halyard",
          "halyard"
        ],
        [
          "lookout",
          "lookout"
        ]
      ],
      "raw_glosses": [
        "(nautical) On a wooden mast, a circular disc (or sometimes a rectangle) of wood near or at the top of the mast, usually with holes or sheaves to reeve signal halyards; also a temporary or emergency place for a lookout."
      ],
      "related": [
        {
          "word": "crow's nest"
        },
        {
          "word": "mast"
        },
        {
          "word": "mainmast"
        },
        {
          "word": "truck"
        }
      ],
      "topics": [
        "nautical",
        "transport"
      ],
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "nautical: circular disc at or near the top of main mast",
          "word": "isomärssy"
        }
      ]
    }
  ],
  "word": "main-truck"
}

{
  "etymology_text": "\"Main\" refers to the mainmast, whereas a truck on another mast may be called (on the mizzenmast, for example) \"mizzen-truck\".",
  "forms": [
    {
      "form": "main-trucks",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "main-truck (plural main-trucks)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "crow's nest"
    },
    {
      "word": "mast"
    },
    {
      "word": "mainmast"
    },
    {
      "word": "truck"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "en:Nautical"
      ],
      "glosses": [
        "On a wooden mast, a circular disc (or sometimes a rectangle) of wood near or at the top of the mast, usually with holes or sheaves to reeve signal halyards; also a temporary or emergency place for a lookout."
      ],
      "links": [
        [
          "nautical",
          "nautical"
        ],
        [
          "mast",
          "mast"
        ],
        [
          "sheaves",
          "sheaves"
        ],
        [
          "reeve",
          "reeve"
        ],
        [
          "halyard",
          "halyard"
        ],
        [
          "lookout",
          "lookout"
        ]
      ],
      "raw_glosses": [
        "(nautical) On a wooden mast, a circular disc (or sometimes a rectangle) of wood near or at the top of the mast, usually with holes or sheaves to reeve signal halyards; also a temporary or emergency place for a lookout."
      ],
      "topics": [
        "nautical",
        "transport"
      ]
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "nautical: circular disc at or near the top of main mast",
      "word": "isomärssy"
    }
  ],
  "word": "main-truck"
}