var keywordQuery = new Microsoft.SharePoint.Client.Search.Query.KeywordQuery(context);
    keywordQuery.set_queryText("queryText here");
    keywordQuery.set_trimDuplicates(false);
    keywordQuery.set_rowLimit(500);
    var searchExecutor = new Microsoft.SharePoint.Client.Search.Query.SearchExecutor(context);
    results = searchExecutor.executeQuery(keywordQuery);

    context.executeQueryAsync(onQuerySuccess, onQueryFail);

function onQuerySuccess() {
    $.each(results.m_value.ResultTables[0].ResultRows, function () {

        console.log(this.Title + ' - ' + this.Author);

        // I want managed metadata column value here (same as Title & Author) if managed metadata column is exist in the search result

    });
}