"two-forty" meaning in English

{
  "etymology_text": "Referring to the sport of trotting (harness racing), in which running a mile in two minutes and forty seconds was considered a very fast pace in 19th-century America.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "two-forty (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "American English",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Forty",
          "orig": "en:Forty",
          "parents": [
            "Numbers",
            "All topics",
            "Terms by semantic function",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Two",
          "orig": "en:Two",
          "parents": [
            "Numbers",
            "All topics",
            "Terms by semantic function",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "derived": [
        {
          "word": "two-forty on a plank road"
        }
      ],
      "glosses": [
        "A very fast speed."
      ],
      "id": "en-two-forty-en-noun-odYB3YyW",
      "links": [
        [
          "fast",
          "fast"
        ],
        [
          "speed",
          "speed"
        ]
      ],
      "raw_glosses": [
        "(US, slang, obsolete) A very fast speed."
      ],
      "synonyms": [
        {
          "word": "2:40"
        },
        {
          "word": "two forty"
        }
      ],
      "tags": [
        "US",
        "obsolete",
        "slang",
        "uncountable"
      ]
    }
  ],
  "word": "two-forty"
}

{
  "derived": [
    {
      "word": "two-forty on a plank road"
    }
  ],
  "etymology_text": "Referring to the sport of trotting (harness racing), in which running a mile in two minutes and forty seconds was considered a very fast pace in 19th-century America.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "two-forty (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "American English",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English slang",
        "English terms with obsolete senses",
        "English uncountable nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Forty",
        "en:Two"
      ],
      "glosses": [
        "A very fast speed."
      ],
      "links": [
        [
          "fast",
          "fast"
        ],
        [
          "speed",
          "speed"
        ]
      ],
      "raw_glosses": [
        "(US, slang, obsolete) A very fast speed."
      ],
      "tags": [
        "US",
        "obsolete",
        "slang",
        "uncountable"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "2:40"
    },
    {
      "word": "two forty"
    }
  ],
  "word": "two-forty"
}