"see a man about a horse" meaning in Anglais

{
  "categories": [
    {
      "kind": "other",
      "name": "Compositions en anglais",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Locutions nominales en anglais",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Anglais",
      "orig": "anglais",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_texts": [
    "Composé de see (« voir »), man (« un »), a (« homme »), about, a et horse (« cheval »)."
  ],
  "lang": "Anglais",
  "lang_code": "en",
  "pos": "noun",
  "pos_title": "Locution nominale",
  "raw_tags": [
    "se conjugue : → voir la conjugaison de see"
  ],
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Métaphores en anglais",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Termes vieillis en anglais",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Aller aux toilettes."
      ],
      "id": "fr-see_a_man_about_a_horse-en-noun-akjhR6S5",
      "tags": [
        "dated",
        "figuratively"
      ]
    }
  ],
  "word": "see a man about a horse"
}

{
  "categories": [
    "Compositions en anglais",
    "Locutions nominales en anglais",
    "anglais"
  ],
  "etymology_texts": [
    "Composé de see (« voir »), man (« un »), a (« homme »), about, a et horse (« cheval »)."
  ],
  "lang": "Anglais",
  "lang_code": "en",
  "pos": "noun",
  "pos_title": "Locution nominale",
  "raw_tags": [
    "se conjugue : → voir la conjugaison de see"
  ],
  "senses": [
    {
      "categories": [
        "Métaphores en anglais",
        "Termes vieillis en anglais"
      ],
      "glosses": [
        "Aller aux toilettes."
      ],
      "tags": [
        "dated",
        "figuratively"
      ]
    }
  ],
  "word": "see a man about a horse"
}