"simple engine" meaning in English

{
  "forms": [
    {
      "form": "simple engines",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "simple engine (plural simple engines)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "_dis": "79 21",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "An engine that has only a single stage, contrasting to a compound engine, compound locomotive, or triple expansion engine, which use multiple stages to improve efficiency."
      ],
      "id": "en-simple_engine-en-noun-23SzBoUx",
      "links": [
        [
          "engine",
          "engine"
        ],
        [
          "compound engine",
          "compound engine"
        ],
        [
          "compound locomotive",
          "compound locomotive"
        ],
        [
          "triple expansion engine",
          "triple expansion engine"
        ]
      ]
    },
    {
      "glosses": [
        "A steam engine that does not use a separate condenser to create suction and thereby improve efficiency."
      ],
      "id": "en-simple_engine-en-noun-aunDrAV9",
      "links": [
        [
          "steam engine",
          "steam engine"
        ],
        [
          "condenser",
          "condenser"
        ]
      ]
    }
  ],
  "wikipedia": [
    "simple engine"
  ],
  "word": "simple engine"
}

{
  "categories": [
    "English countable nouns",
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English nouns"
  ],
  "forms": [
    {
      "form": "simple engines",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "simple engine (plural simple engines)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "glosses": [
        "An engine that has only a single stage, contrasting to a compound engine, compound locomotive, or triple expansion engine, which use multiple stages to improve efficiency."
      ],
      "links": [
        [
          "engine",
          "engine"
        ],
        [
          "compound engine",
          "compound engine"
        ],
        [
          "compound locomotive",
          "compound locomotive"
        ],
        [
          "triple expansion engine",
          "triple expansion engine"
        ]
      ]
    },
    {
      "glosses": [
        "A steam engine that does not use a separate condenser to create suction and thereby improve efficiency."
      ],
      "links": [
        [
          "steam engine",
          "steam engine"
        ],
        [
          "condenser",
          "condenser"
        ]
      ]
    }
  ],
  "wikipedia": [
    "simple engine"
  ],
  "word": "simple engine"
}