"U engine" meaning in English

{
  "forms": [
    {
      "form": "U engines",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "U engine (plural U engines)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "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 entries with language name categories using raw markup",
          "parents": [
            "Entries with language name categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A piston engine made up of two separate straight engines (complete with separate crankshafts) placed side by side and coupled to a shared output shaft."
      ],
      "id": "en-U_engine-en-noun-Z6hcQUw7",
      "links": [
        [
          "piston engine",
          "piston engine"
        ],
        [
          "straight engine",
          "straight engine"
        ],
        [
          "crankshaft",
          "crankshaft"
        ],
        [
          "output",
          "output"
        ],
        [
          "shaft",
          "shaft"
        ]
      ]
    }
  ],
  "word": "U engine"
}

{
  "forms": [
    {
      "form": "U engines",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "U engine (plural U engines)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English entries with language name categories using raw markup",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms derived from the shape of letters",
        "English terms with non-redundant non-automated sortkeys"
      ],
      "glosses": [
        "A piston engine made up of two separate straight engines (complete with separate crankshafts) placed side by side and coupled to a shared output shaft."
      ],
      "links": [
        [
          "piston engine",
          "piston engine"
        ],
        [
          "straight engine",
          "straight engine"
        ],
        [
          "crankshaft",
          "crankshaft"
        ],
        [
          "output",
          "output"
        ],
        [
          "shaft",
          "shaft"
        ]
      ]
    }
  ],
  "word": "U engine"
}