"underexpression" meaning in English

{
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      "expansion": "under- + expression",
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  ],
  "etymology_text": "under- + expression",
  "forms": [
    {
      "form": "underexpressions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
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      "expansion": "underexpression (countable and uncountable, plural underexpressions)",
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
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      "examples": [
        {
          "text": "the underexpression of certain genes"
        },
        {
          "text": "your underexpression of passion"
        }
      ],
      "glosses": [
        "Insufficient or abnormally low expression"
      ],
      "id": "en-underexpression-en-noun-zYvbK4WW",
      "links": [
        [
          "expression",
          "expression"
        ]
      ],
      "related": [
        {
          "word": "overexpression"
        },
        {
          "word": "underexpresser"
        },
        {
          "word": "underexpressive"
        }
      ],
      "tags": [
        "countable",
        "uncountable"
      ]
    }
  ],
  "word": "underexpression"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "under",
        "3": "expression"
      },
      "expansion": "under- + expression",
      "name": "prefix"
    }
  ],
  "etymology_text": "under- + expression",
  "forms": [
    {
      "form": "underexpressions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "underexpression (countable and uncountable, plural underexpressions)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "overexpression"
    },
    {
      "word": "underexpresser"
    },
    {
      "word": "underexpressive"
    }
  ],
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        "English nouns",
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      ],
      "examples": [
        {
          "text": "the underexpression of certain genes"
        },
        {
          "text": "your underexpression of passion"
        }
      ],
      "glosses": [
        "Insufficient or abnormally low expression"
      ],
      "links": [
        [
          "expression",
          "expression"
        ]
      ],
      "tags": [
        "countable",
        "uncountable"
      ]
    }
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  "word": "underexpression"
}