"rarefact" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "frm",
        "3": "raréfaction"
      },
      "expansion": "Middle French raréfaction",
      "name": "uder"
    }
  ],
  "etymology_text": "From Middle French raréfaction.",
  "forms": [
    {
      "form": "rarefacts",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "rarefacting",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "rarefacted",
      "tags": [
        "participle",
        "past"
      ]
    },
    {
      "form": "rarefacted",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "rarefact (third-person singular simple present rarefacts, present participle rarefacting, simple past and past participle rarefacted)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "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 undefined derivations",
          "parents": [
            "Undefined derivations",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2013, Beth Schrope, Surgical and Interventional Ultrasound",
          "text": "As the ultrasound wave compresses and rarefacts through the medium, it causes microbubbles in the tissue to contract and expand.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "To reduce in density."
      ],
      "id": "en-rarefact-en-verb-bzAhp1XW",
      "links": [
        [
          "transitive",
          "transitive"
        ],
        [
          "intransitive",
          "intransitive"
        ],
        [
          "reduce",
          "reduce"
        ],
        [
          "density",
          "density"
        ]
      ],
      "raw_glosses": [
        "(transitive, intransitive) To reduce in density."
      ],
      "related": [
        {
          "word": "rarefaction"
        }
      ],
      "tags": [
        "intransitive",
        "transitive"
      ],
      "translations": [
        {
          "code": "ru",
          "lang": "Russian",
          "roman": "razredítʹ",
          "sense": "reduce in density",
          "word": "разреди́ть"
        }
      ]
    }
  ],
  "word": "rarefact"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "frm",
        "3": "raréfaction"
      },
      "expansion": "Middle French raréfaction",
      "name": "uder"
    }
  ],
  "etymology_text": "From Middle French raréfaction.",
  "forms": [
    {
      "form": "rarefacts",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "rarefacting",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "rarefacted",
      "tags": [
        "participle",
        "past"
      ]
    },
    {
      "form": "rarefacted",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "rarefact (third-person singular simple present rarefacts, present participle rarefacting, simple past and past participle rarefacted)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "related": [
    {
      "word": "rarefaction"
    }
  ],
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English intransitive verbs",
        "English lemmas",
        "English terms derived from Middle French",
        "English terms with quotations",
        "English transitive verbs",
        "English undefined derivations",
        "English verbs"
      ],
      "examples": [
        {
          "ref": "2013, Beth Schrope, Surgical and Interventional Ultrasound",
          "text": "As the ultrasound wave compresses and rarefacts through the medium, it causes microbubbles in the tissue to contract and expand.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "To reduce in density."
      ],
      "links": [
        [
          "transitive",
          "transitive"
        ],
        [
          "intransitive",
          "intransitive"
        ],
        [
          "reduce",
          "reduce"
        ],
        [
          "density",
          "density"
        ]
      ],
      "raw_glosses": [
        "(transitive, intransitive) To reduce in density."
      ],
      "tags": [
        "intransitive",
        "transitive"
      ]
    }
  ],
  "translations": [
    {
      "code": "ru",
      "lang": "Russian",
      "roman": "razredítʹ",
      "sense": "reduce in density",
      "word": "разреди́ть"
    }
  ],
  "word": "rarefact"
}