"millirem" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "milli<id:thousandth>",
        "3": "rem"
      },
      "expansion": "milli- + rem",
      "name": "prefix"
    }
  ],
  "etymology_text": "From milli- + rem.",
  "forms": [
    {
      "form": "millirems",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "millirem (plural millirems)",
      "name": "en-noun"
    }
  ],
  "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"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with milli- (thousandth)",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "One thousandth of a rem"
      ],
      "id": "en-millirem-en-noun-NTJK3yUK",
      "links": [
        [
          "rem",
          "rem"
        ]
      ],
      "synonyms": [
        {
          "word": "mrem"
        }
      ]
    }
  ],
  "word": "millirem"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "milli<id:thousandth>",
        "3": "rem"
      },
      "expansion": "milli- + rem",
      "name": "prefix"
    }
  ],
  "etymology_text": "From milli- + rem.",
  "forms": [
    {
      "form": "millirems",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "millirem (plural millirems)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English terms prefixed with milli- (thousandth)",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "One thousandth of a rem"
      ],
      "links": [
        [
          "rem",
          "rem"
        ]
      ]
    }
  ],
  "synonyms": [
    {
      "word": "mrem"
    }
  ],
  "word": "millirem"
}