"underactive" meaning in English

{
  "antonyms": [
    {
      "word": "overactive"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "under",
        "3": "active"
      },
      "expansion": "under- + active",
      "name": "prefix"
    }
  ],
  "etymology_text": "under- + active",
  "forms": [
    {
      "form": "more underactive",
      "tags": [
        "comparative"
      ]
    },
    {
      "form": "most underactive",
      "tags": [
        "superlative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "underactive (comparative more underactive, superlative most underactive)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with language name categories using raw markup",
          "parents": [
            "Entries with language name categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English hybridisms",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with under-",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1989 Apr, John A. McDougall, “Healthy by Choice”, in Vegetarian Times",
          "text": "Thus a person with an underactive thyroid can gain weight even on a low-calorie diet.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Less than normally active."
      ],
      "id": "en-underactive-en-adj-KdO7ZLRZ",
      "links": [
        [
          "active",
          "active"
        ]
      ],
      "synonyms": [
        {
          "word": "hypoactive"
        }
      ]
    }
  ],
  "sounds": [
    {
      "rhymes": "-æktɪv"
    }
  ],
  "word": "underactive"
}

{
  "antonyms": [
    {
      "word": "overactive"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "under",
        "3": "active"
      },
      "expansion": "under- + active",
      "name": "prefix"
    }
  ],
  "etymology_text": "under- + active",
  "forms": [
    {
      "form": "more underactive",
      "tags": [
        "comparative"
      ]
    },
    {
      "form": "most underactive",
      "tags": [
        "superlative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "underactive (comparative more underactive, superlative most underactive)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English 4-syllable words",
        "English adjectives",
        "English entries with incorrect language header",
        "English entries with language name categories using raw markup",
        "English hybridisms",
        "English lemmas",
        "English terms prefixed with under-",
        "English terms with quotations",
        "Rhymes:English/æktɪv",
        "Rhymes:English/æktɪv/4 syllables"
      ],
      "examples": [
        {
          "ref": "1989 Apr, John A. McDougall, “Healthy by Choice”, in Vegetarian Times",
          "text": "Thus a person with an underactive thyroid can gain weight even on a low-calorie diet.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Less than normally active."
      ],
      "links": [
        [
          "active",
          "active"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "rhymes": "-æktɪv"
    }
  ],
  "synonyms": [
    {
      "word": "hypoactive"
    }
  ],
  "word": "underactive"
}