"know one's shit" meaning in English

{
  "forms": [
    {
      "form": "knows one's shit",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "knowing one's shit",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "knew one's shit",
      "tags": [
        "past"
      ]
    },
    {
      "form": "known one's shit",
      "tags": [
        "participle",
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "know<,,knew,known> one's shit"
      },
      "expansion": "know one's shit (third-person singular simple present knows one's shit, present participle knowing one's shit, simple past knew one's shit, past participle known one's shit)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "Joe really knows his shit when it comes to plumbing.",
          "type": "example"
        },
        {
          "ref": "2005, Mike Tucker, Among Warriors in Iraq",
          "text": "\"He really knows his shit. He knows more about guerrilla war than I could ever learn in ten lifetimes,\" Morales said.",
          "type": "quotation"
        },
        {
          "ref": "2011, Lev Grossman, The Magician King, page 134",
          "text": "“Any magician can ask another magician of equal or lower level to demonstrate the test corresponding to their level or any of the levels below that,” she recited. “To prove they know their shit.”",
          "type": "quotation"
        },
        {
          "ref": "2014, Dalton Fury, Full Assault Mode: A Delta Force Novel",
          "text": "She knew her shit. . . . Without as much as a single stutter or misstep, she spoke about decisive point, synergistic execution, momentum shift, kinetic solution, and competent authority.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Synonym of know one's stuff, to be knowledgeable about a subject or task."
      ],
      "id": "en-know_one's_shit-en-verb-NotEKwJg",
      "links": [
        [
          "know one's stuff",
          "know one's stuff#English"
        ],
        [
          "knowledgeable",
          "knowledgeable"
        ],
        [
          "subject",
          "subject"
        ],
        [
          "task",
          "task"
        ]
      ],
      "raw_glosses": [
        "(idiomatic, vulgar) Synonym of know one's stuff, to be knowledgeable about a subject or task."
      ],
      "synonyms": [
        {
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "know one's stuff"
        },
        {
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "to be knowledgeable about a subject or task"
        }
      ],
      "tags": [
        "idiomatic",
        "vulgar"
      ]
    }
  ],
  "sounds": [
    {
      "audio": "En-au-know one's shit.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/7/74/En-au-know_one%27s_shit.ogg/En-au-know_one%27s_shit.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/7/74/En-au-know_one%27s_shit.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "word": "know one's shit"
}

{
  "forms": [
    {
      "form": "knows one's shit",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "knowing one's shit",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "knew one's shit",
      "tags": [
        "past"
      ]
    },
    {
      "form": "known one's shit",
      "tags": [
        "participle",
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "know<,,knew,known> one's shit"
      },
      "expansion": "know one's shit (third-person singular simple present knows one's shit, present participle knowing one's shit, simple past knew one's shit, past participle known one's shit)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English idioms",
        "English lemmas",
        "English multiword terms",
        "English terms with audio links",
        "English terms with quotations",
        "English terms with usage examples",
        "English verbs",
        "English vulgarities"
      ],
      "examples": [
        {
          "text": "Joe really knows his shit when it comes to plumbing.",
          "type": "example"
        },
        {
          "ref": "2005, Mike Tucker, Among Warriors in Iraq",
          "text": "\"He really knows his shit. He knows more about guerrilla war than I could ever learn in ten lifetimes,\" Morales said.",
          "type": "quotation"
        },
        {
          "ref": "2011, Lev Grossman, The Magician King, page 134",
          "text": "“Any magician can ask another magician of equal or lower level to demonstrate the test corresponding to their level or any of the levels below that,” she recited. “To prove they know their shit.”",
          "type": "quotation"
        },
        {
          "ref": "2014, Dalton Fury, Full Assault Mode: A Delta Force Novel",
          "text": "She knew her shit. . . . Without as much as a single stutter or misstep, she spoke about decisive point, synergistic execution, momentum shift, kinetic solution, and competent authority.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Synonym of know one's stuff, to be knowledgeable about a subject or task."
      ],
      "links": [
        [
          "know one's stuff",
          "know one's stuff#English"
        ],
        [
          "knowledgeable",
          "knowledgeable"
        ],
        [
          "subject",
          "subject"
        ],
        [
          "task",
          "task"
        ]
      ],
      "raw_glosses": [
        "(idiomatic, vulgar) Synonym of know one's stuff, to be knowledgeable about a subject or task."
      ],
      "synonyms": [
        {
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "know one's stuff"
        },
        {
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "to be knowledgeable about a subject or task"
        }
      ],
      "tags": [
        "idiomatic",
        "vulgar"
      ]
    }
  ],
  "sounds": [
    {
      "audio": "En-au-know one's shit.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/7/74/En-au-know_one%27s_shit.ogg/En-au-know_one%27s_shit.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/7/74/En-au-know_one%27s_shit.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "word": "know one's shit"
}