"mmhm" meaning in English

{
  "head_templates": [
    {
      "args": {},
      "expansion": "mmhm",
      "name": "en-interj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "intj",
  "senses": [
    {
      "alt_of": [
        {
          "word": "mhm"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1960, American Psychological Association, Journal of Experimental Psychology",
          "text": "Such errors, since they precede the first reinforcement of a correct response by \"mmhm,\" do not depend on the reinforcement value of \"mmhm\"...",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Alternative spelling of mhm"
      ],
      "id": "en-mmhm-en-intj-YfbqGxoB",
      "links": [
        [
          "mhm",
          "mhm#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "mmhm"
}

{
  "head_templates": [
    {
      "args": {},
      "expansion": "mmhm",
      "name": "en-interj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "intj",
  "senses": [
    {
      "alt_of": [
        {
          "word": "mhm"
        }
      ],
      "categories": [
        "English entries with incorrect language header",
        "English interjections",
        "English lemmas",
        "English terms with quotations",
        "English words without vowels",
        "Quotation templates to be cleaned"
      ],
      "examples": [
        {
          "ref": "1960, American Psychological Association, Journal of Experimental Psychology",
          "text": "Such errors, since they precede the first reinforcement of a correct response by \"mmhm,\" do not depend on the reinforcement value of \"mmhm\"...",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Alternative spelling of mhm"
      ],
      "links": [
        [
          "mhm",
          "mhm#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "mmhm"
}