How do I create a Key and Values Dictionary array in C#

I have created dictionaries before but in vb.net
where i would do this

 Private degreeDictionary As Dictionary(Of String, String())

    Public Sub kanjsort()

        degreeDictionary= New Dictionary(Of String, String())
       
        degreeDictionary.Add("ups", {"updegree", "popup"})

End sub

in C# a generally similar method is used

Dictionary<string, string> degreeDictionary= new Dictionary<string,string>();

Void Start ()
{
degreeDictionary.add("upps","updata","goingup");


}

I have been looking around but I havent seen any references to keys and values array type dictionary .

how can I create an array dictionaty that can hold keys and values in this manner
degreeDictionary.Add(“ups”, {“updegree”, “popup”})… or something like this

Dictionary<string, string> dictionary = new Dictionary<string, string>();

and then

dictionary.Add("ups", new string[] {"updegree", "popup"});

or

dictionary.Add("ups", new[] {"updegree", "popup"});