"trunnion plate" meaning in English

{
  "forms": [
    {
      "form": "trunnion plates",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "trunnion plate (plural trunnion plates)",
      "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": "Firearms",
          "orig": "en:Firearms",
          "parents": [
            "Weapons",
            "Hunting",
            "Military",
            "Tools",
            "Human activity",
            "Society",
            "Technology",
            "Human behaviour",
            "All topics",
            "Human",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A raised rim forming a shoulder around the trunnion of a gun."
      ],
      "id": "en-trunnion_plate-en-noun-LdcQ3LMp"
    }
  ],
  "word": "trunnion plate"
}

{
  "forms": [
    {
      "form": "trunnion plates",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "trunnion plate (plural trunnion plates)",
      "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",
        "en:Firearms"
      ],
      "glosses": [
        "A raised rim forming a shoulder around the trunnion of a gun."
      ]
    }
  ],
  "word": "trunnion plate"
}