WordReference Spanish Monolingual

[exudis]

    {
        "dictName": "WordReference Monolingual Spanish", 
        "windowUrl": "https://www.wordreference.com/definicion/<word>",
        "css": "header, body #ad1 { display: none !important;} body { margin-top: 50px !important;}"
    }

[river]

Changed a little bit css, have a try.