How to generate sequence of nodes for synonyms

 using System.Collections.Generic;
 
 public class WordNode {
     public string Word { private set; get; }
     public List<WordNode> synonyms;
     public WordNode(string word) {
         Word = word;
         synonyms = new List<WordNode>();
     }
 }
 
 public class SynonymApp {
     public Dictionary<string, WordNode> dict;
     public void Init() {
        var words = new string[4];
        words[0] = "strong";
        words[1] = "powerful";
        words[2] = "rock";
        words[3] = "stone";
 
        dict = new Dictionary<string, WordNode>();
        foreach (var w in words) {
             dict.Add(w, new WordNode(w));
        }
 
        dict["strong"].synonyms.Add(dict["powerful"]);
        dict["rock"].synonyms.Add(dict["stone"]);
     }
 }

That's a simple example. How you populate the data is another thing.