"jackknife clam" meaning in English

{
  "forms": [
    {
      "form": "jackknife clams",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "jackknife clam (plural jackknife clams)",
      "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": "Bivalves",
          "orig": "en:Bivalves",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "common name for several species of saltwater shellfish in the family Solenidae; also known as razor shells. Their shells are long and narrow, suggesting a folded jackknife or cut-throat razor"
      ],
      "id": "en-jackknife_clam-en-noun-lHkYFacE",
      "links": [
        [
          "razor shells",
          "razor shells"
        ],
        [
          "jackknife",
          "jackknife"
        ],
        [
          "cut-throat razor",
          "cut-throat razor"
        ]
      ]
    }
  ],
  "word": "jackknife clam"
}

{
  "forms": [
    {
      "form": "jackknife clams",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "jackknife clam (plural jackknife clams)",
      "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",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Bivalves"
      ],
      "glosses": [
        "common name for several species of saltwater shellfish in the family Solenidae; also known as razor shells. Their shells are long and narrow, suggesting a folded jackknife or cut-throat razor"
      ],
      "links": [
        [
          "razor shells",
          "razor shells"
        ],
        [
          "jackknife",
          "jackknife"
        ],
        [
          "cut-throat razor",
          "cut-throat razor"
        ]
      ]
    }
  ],
  "word": "jackknife clam"
}