"SJK" meaning in Japanese

{
  "etymology_templates": [
    {
      "args": {
        "1": "S",
        "2": "エス",
        "3": "J%K",
        "4": "ジェー%ケー",
        "pos1": "first letter of English <i class=\"Latn mention\" lang=\"en\">second</i>",
        "t2": "female high school student"
      },
      "expansion": "S(エス) (esu, first letter of English second) + J(ジェー)K(ケー) (jēkē, “female high school student”)",
      "name": "com-ja"
    }
  ],
  "etymology_text": "Compound of S(エス) (esu, first letter of English second) + J(ジェー)K(ケー) (jēkē, “female high school student”).",
  "forms": [
    {
      "form": "SJK",
      "ruby": [
        [
          "SJK",
          "エスジェーケー"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "esujēkē",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "エスジェーケー"
      },
      "expansion": "SJK(エスジェーケー) • (esujēkē)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Japanese entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese links with redundant alt parameters",
          "parents": [
            "Links with redundant alt parameters",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese links with redundant wikilinks",
          "parents": [
            "Links with redundant wikilinks",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with redundant sortkeys",
          "parents": [
            "Terms with redundant sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 2 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "second-year female high school student, female eleventh-grade student"
      ],
      "id": "en-SJK-ja-noun-rBNO5kxW",
      "related": [
        {
          "alt": "efujēkē",
          "ruby": [
            [
              "F",
              "エフ"
            ],
            [
              "J",
              "ジェー"
            ],
            [
              "K",
              "ケー"
            ]
          ],
          "word": "FJK"
        },
        {
          "alt": "emujēkē",
          "ruby": [
            [
              "M",
              "エム"
            ],
            [
              "J",
              "ジェー"
            ],
            [
              "K",
              "ケー"
            ]
          ],
          "word": "MJK"
        },
        {
          "alt": "erujēkē",
          "ruby": [
            [
              "L",
              "エル"
            ],
            [
              "J",
              "ジェー"
            ],
            [
              "K",
              "ケー"
            ]
          ],
          "word": "LJK"
        }
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[e̞sɨʑe̞ːke̞ː]"
    }
  ],
  "word": "SJK"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "S",
        "2": "エス",
        "3": "J%K",
        "4": "ジェー%ケー",
        "pos1": "first letter of English <i class=\"Latn mention\" lang=\"en\">second</i>",
        "t2": "female high school student"
      },
      "expansion": "S(エス) (esu, first letter of English second) + J(ジェー)K(ケー) (jēkē, “female high school student”)",
      "name": "com-ja"
    }
  ],
  "etymology_text": "Compound of S(エス) (esu, first letter of English second) + J(ジェー)K(ケー) (jēkē, “female high school student”).",
  "forms": [
    {
      "form": "SJK",
      "ruby": [
        [
          "SJK",
          "エスジェーケー"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "esujēkē",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "エスジェーケー"
      },
      "expansion": "SJK(エスジェーケー) • (esujēkē)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "related": [
    {
      "alt": "efujēkē",
      "ruby": [
        [
          "F",
          "エフ"
        ],
        [
          "J",
          "ジェー"
        ],
        [
          "K",
          "ケー"
        ]
      ],
      "word": "FJK"
    },
    {
      "alt": "emujēkē",
      "ruby": [
        [
          "M",
          "エム"
        ],
        [
          "J",
          "ジェー"
        ],
        [
          "K",
          "ケー"
        ]
      ],
      "word": "MJK"
    },
    {
      "alt": "erujēkē",
      "ruby": [
        [
          "L",
          "エル"
        ],
        [
          "J",
          "ジェー"
        ],
        [
          "K",
          "ケー"
        ]
      ],
      "word": "LJK"
    }
  ],
  "senses": [
    {
      "categories": [
        "Japanese compound terms",
        "Japanese entries with incorrect language header",
        "Japanese lemmas",
        "Japanese links with redundant alt parameters",
        "Japanese links with redundant wikilinks",
        "Japanese nouns",
        "Japanese terms with IPA pronunciation",
        "Japanese terms with IPA pronunciation missing pitch accent",
        "Japanese terms with redundant sortkeys",
        "Pages with 2 entries",
        "Pages with entries"
      ],
      "glosses": [
        "second-year female high school student, female eleventh-grade student"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[e̞sɨʑe̞ːke̞ː]"
    }
  ],
  "word": "SJK"
}