"1ºs" meaning in Portuguese

{
  "etymology_templates": [
    {
      "args": {
        "1": "pt",
        "2": "primeiros"
      },
      "expansion": "Abbreviation of primeiros.",
      "name": "abbreviation of"
    }
  ],
  "etymology_text": "Abbreviation of primeiros.",
  "head_templates": [
    {
      "args": {
        "1": "pt",
        "2": "adjective form"
      },
      "expansion": "1ºs",
      "name": "head"
    }
  ],
  "lang": "Portuguese",
  "lang_code": "pt",
  "pos": "num",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Portuguese entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "word": "1º"
        }
      ],
      "glosses": [
        "masculine plural of 1º"
      ],
      "id": "en-1ºs-pt-num-QYywM7~k",
      "links": [
        [
          "1º",
          "1º#Portuguese"
        ]
      ],
      "tags": [
        "form-of",
        "masculine",
        "plural"
      ]
    }
  ],
  "word": "1ºs"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "pt",
        "2": "primeiros"
      },
      "expansion": "Abbreviation of primeiros.",
      "name": "abbreviation of"
    }
  ],
  "etymology_text": "Abbreviation of primeiros.",
  "head_templates": [
    {
      "args": {
        "1": "pt",
        "2": "adjective form"
      },
      "expansion": "1ºs",
      "name": "head"
    }
  ],
  "lang": "Portuguese",
  "lang_code": "pt",
  "pos": "num",
  "senses": [
    {
      "categories": [
        "Pages with 1 entry",
        "Pages with entries",
        "Portuguese abbreviations",
        "Portuguese adjective forms",
        "Portuguese entries with incorrect language header",
        "Portuguese non-lemma forms",
        "Portuguese terms spelled with numbers",
        "Portuguese terms spelled with º"
      ],
      "form_of": [
        {
          "word": "1º"
        }
      ],
      "glosses": [
        "masculine plural of 1º"
      ],
      "links": [
        [
          "1º",
          "1º#Portuguese"
        ]
      ],
      "tags": [
        "form-of",
        "masculine",
        "plural"
      ]
    }
  ],
  "word": "1ºs"
}