"treat of" meaning in English

{
  "forms": [
    {
      "form": "treats of",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "treating of",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "treated of",
      "tags": [
        "participle",
        "past"
      ]
    },
    {
      "form": "treated of",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "*"
      },
      "expansion": "treat of (third-person singular simple present treats of, present participle treating of, simple past and past participle treated of)",
      "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 phrasal verbs formed with \"of\"",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1905, Charles Rochester Eastman, A brief general account of fossil fishes",
          "text": "In the same way, palaeichthyology, or that branch of natural science which treats of fossil fishes, extends our information from the existing fauna back to the earliest advent of vertebrate life upon our globe […]",
          "type": "quotation"
        }
      ],
      "glosses": [
        "To deal with (a subject)."
      ],
      "id": "en-treat_of-en-verb-VgtcZWcM",
      "raw_glosses": [
        "(dated) To deal with (a subject)."
      ],
      "tags": [
        "dated"
      ]
    }
  ],
  "word": "treat of"
}

{
  "forms": [
    {
      "form": "treats of",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "treating of",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "treated of",
      "tags": [
        "participle",
        "past"
      ]
    },
    {
      "form": "treated of",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "*"
      },
      "expansion": "treat of (third-person singular simple present treats of, present participle treating of, simple past and past participle treated of)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        "English dated terms",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English phrasal verbs",
        "English phrasal verbs formed with \"of\"",
        "English terms with quotations",
        "English verbs",
        "Quotation templates to be cleaned"
      ],
      "examples": [
        {
          "ref": "1905, Charles Rochester Eastman, A brief general account of fossil fishes",
          "text": "In the same way, palaeichthyology, or that branch of natural science which treats of fossil fishes, extends our information from the existing fauna back to the earliest advent of vertebrate life upon our globe […]",
          "type": "quotation"
        }
      ],
      "glosses": [
        "To deal with (a subject)."
      ],
      "raw_glosses": [
        "(dated) To deal with (a subject)."
      ],
      "tags": [
        "dated"
      ]
    }
  ],
  "word": "treat of"
}