"m." meaning in Spanish

{
  "etymology_templates": [
    {
      "args": {
        "1": "es",
        "2": "la",
        "3": "meridiēs",
        "4": "",
        "5": "noon"
      },
      "expansion": "Latin meridiēs (“noon”)",
      "name": "der"
    }
  ],
  "etymology_text": "Abbreviation of Latin meridiēs (“noon”).",
  "head_templates": [
    {
      "args": {
        "1": "es",
        "2": "noun"
      },
      "expansion": "m.",
      "name": "head"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages with 10 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Spanish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "es",
          "name": "Time",
          "orig": "es:Time",
          "parents": [
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "noon"
      ],
      "id": "en-m.-es-noun-sZjzzY5w",
      "links": [
        [
          "noon",
          "noon"
        ]
      ],
      "related": [
        {
          "word": "a. m."
        },
        {
          "word": "p. m."
        }
      ]
    }
  ],
  "word": "m."
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "es",
        "2": "la",
        "3": "meridiēs",
        "4": "",
        "5": "noon"
      },
      "expansion": "Latin meridiēs (“noon”)",
      "name": "der"
    }
  ],
  "etymology_text": "Abbreviation of Latin meridiēs (“noon”).",
  "head_templates": [
    {
      "args": {
        "1": "es",
        "2": "noun"
      },
      "expansion": "m.",
      "name": "head"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "related": [
    {
      "word": "a. m."
    },
    {
      "word": "p. m."
    }
  ],
  "senses": [
    {
      "categories": [
        "Pages with 10 entries",
        "Pages with entries",
        "Spanish entries with incorrect language header",
        "Spanish lemmas",
        "Spanish nouns",
        "Spanish terms derived from Latin",
        "Spanish terms spelled with .",
        "es:Time"
      ],
      "glosses": [
        "noon"
      ],
      "links": [
        [
          "noon",
          "noon"
        ]
      ]
    }
  ],
  "word": "m."
}