"mus" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "noun form"
      },
      "expansion": "mus",
      "name": "head"
    }
  ],
  "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"
        }
      ],
      "form_of": [
        {
          "word": "mu"
        }
      ],
      "glosses": [
        "plural of mu"
      ],
      "id": "en-mus-en-noun-67-V-us6",
      "links": [
        [
          "mu",
          "mu#English"
        ]
      ],
      "tags": [
        "form-of",
        "plural"
      ]
    }
  ],
  "word": "mus"
}

{
  "categories": [
    "Iu Mien terms in nonstandard scripts",
    "White Hmong entries with incorrect language header",
    "White Hmong interjections",
    "White Hmong lemmas",
    "White Hmong terms derived from Proto-Hmong",
    "White Hmong terms derived from Proto-Hmong-Mien",
    "White Hmong terms inherited from Proto-Hmong",
    "White Hmong terms inherited from Proto-Hmong-Mien",
    "White Hmong terms with IPA pronunciation",
    "White Hmong verbs"
  ],
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "noun form"
      },
      "expansion": "mus",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English non-lemma forms",
        "English noun forms"
      ],
      "form_of": [
        {
          "word": "mu"
        }
      ],
      "glosses": [
        "plural of mu"
      ],
      "links": [
        [
          "mu",
          "mu#English"
        ]
      ],
      "tags": [
        "form-of",
        "plural"
      ]
    }
  ],
  "word": "mus"
}