API de diccionario compatible con Javascript

La API de Pearson funciona.

• gratis hasta 150.000 solicitudes/mes
• admite sinónimos
• da archivos de audio para la pronunciación
• fácil de usar con Javascript, devuelve un objeto JSON

p.ej. para baffle:

{
  "status": 200,
  "offset": 0,
  "limit": 10,
  "count": 2,
  "total": 2,
  "url": "/v2/dictionaries/ldoce5/entries?headword=baffle",
  "results": [
    {
      "datasets": [
        "ldoce5",
        "dictionary",
        "sandbox"
      ],
      "headword": "baffle",
      "homnum": 2,
      "id": "cqAEyaHdvP",
      "part_of_speech": "noun",
      "senses": [
        {
          "definition": [
            "a board, sheet of metal etc that controls the flow of air, water, or sound into or out of something"
          ]
        }
      ],
      "url": "/v2/dictionaries/entries/cqAEyaHdvP"
    },
    {
      "datasets": [
        "ldoce5",
        "dictionary",
        "sandbox"
      ],
      "headword": "baffle",
      "homnum": 1,
      "id": "cqAEyaFCfW",
      "part_of_speech": "verb",
      "pronunciations": [
        {
          "audio": [
            {
              "lang": "British English",
              "type": "pronunciation",
              "url": "/v2/dictionaries/assets/ldoce/gb_pron/baffle_n0205.mp3"
            },
            {
              "lang": "American English",
              "type": "pronunciation",
              "url": "/v2/dictionaries/assets/ldoce/us_pron/baffle1.mp3"
            }
          ],
          "ipa": "ˈbæfəl"
        }
      ],
      "senses": [
        {
          "definition": [
            "if something baffles you, you cannot understand or explain it at all"
          ],
          "examples": [
            {
              "audio": [
                {
                  "type": "example",
                  "url": "/v2/dictionaries/assets/ldoce/exa_pron/p008-000931334.mp3"
                }
              ],
              "text": "The question baffled me completely."
            }
          ]
        }
      ],
      "url": "/v2/dictionaries/entries/cqAEyaFCfW"
    }
  ]
}