"self-propelling" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "self",
        "3": "propelling"
      },
      "expansion": "self- + propelling",
      "name": "prefix"
    }
  ],
  "etymology_text": "From self- + propelling.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "self-propelling (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"
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          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with self-",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1954 March, “Electric Baggage Cars on Liverpool Suburban Lines”, in Railway Magazine, page 197, image caption:",
          "text": "Self-propelling baggage car, converted from a passenger vehicle, for operation over Liverpool electrified lines",
          "type": "quote"
        }
      ],
      "glosses": [
        "Self-propelled."
      ],
      "id": "en-self-propelling-en-adj-3iFuKoai",
      "links": [
        [
          "Self-propelled",
          "self-propelled"
        ]
      ],
      "tags": [
        "not-comparable"
      ]
    }
  ],
  "word": "self-propelling"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "self",
        "3": "propelling"
      },
      "expansion": "self- + propelling",
      "name": "prefix"
    }
  ],
  "etymology_text": "From self- + propelling.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "self-propelling (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 multiword terms",
        "English terms prefixed with self-",
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        "English uncomparable adjectives",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "ref": "1954 March, “Electric Baggage Cars on Liverpool Suburban Lines”, in Railway Magazine, page 197, image caption:",
          "text": "Self-propelling baggage car, converted from a passenger vehicle, for operation over Liverpool electrified lines",
          "type": "quote"
        }
      ],
      "glosses": [
        "Self-propelled."
      ],
      "links": [
        [
          "Self-propelled",
          "self-propelled"
        ]
      ],
      "tags": [
        "not-comparable"
      ]
    }
  ],
  "word": "self-propelling"
}