"unsent" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "enm",
        "3": "unsent"
      },
      "expansion": "Middle English unsent",
      "name": "inh"
    },
    {
      "args": {
        "1": "en",
        "2": "un-",
        "3": "sent"
      },
      "expansion": "un- + sent",
      "name": "af"
    }
  ],
  "etymology_text": "From Middle English unsent, equivalent to un- + sent.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "unsent (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "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 un-",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "I had several unsent e-mails in my pending file."
        }
      ],
      "glosses": [
        "Not yet sent or transmitted."
      ],
      "id": "en-unsent-en-adj-1~qMHvpW",
      "links": [
        [
          "sent",
          "sent"
        ],
        [
          "transmit",
          "transmit"
        ]
      ],
      "tags": [
        "not-comparable"
      ]
    }
  ],
  "sounds": [
    {
      "rhymes": "-ɛnt"
    }
  ],
  "word": "unsent"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "enm",
        "3": "unsent"
      },
      "expansion": "Middle English unsent",
      "name": "inh"
    },
    {
      "args": {
        "1": "en",
        "2": "un-",
        "3": "sent"
      },
      "expansion": "un- + sent",
      "name": "af"
    }
  ],
  "etymology_text": "From Middle English unsent, equivalent to un- + sent.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "unsent (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English adjectives",
        "English entries with incorrect language header",
        "English lemmas",
        "English terms derived from Middle English",
        "English terms inherited from Middle English",
        "English terms prefixed with un-",
        "English uncomparable adjectives",
        "Rhymes:English/ɛnt",
        "Rhymes:English/ɛnt/2 syllables"
      ],
      "examples": [
        {
          "text": "I had several unsent e-mails in my pending file."
        }
      ],
      "glosses": [
        "Not yet sent or transmitted."
      ],
      "links": [
        [
          "sent",
          "sent"
        ],
        [
          "transmit",
          "transmit"
        ]
      ],
      "tags": [
        "not-comparable"
      ]
    }
  ],
  "sounds": [
    {
      "rhymes": "-ɛnt"
    }
  ],
  "word": "unsent"
}