How to use segue in navigation SWIFT Xcode?

I’m building a simple dictionary app. I’ve gotten it to display words on UItableView while user is searching or not. I’m working on assigning each individual word with its own definition but I’m facing a trouble while setting the destination for each word at words array.

Here is part of my ViewController class and its contents:

import UIKit
class ViewController: UIViewController {

@IBOutlet weak var searchBar: UISearchBar!
@IBOutlet weak var tableView: UITableView!

var wordSearch = [String]()
var wordArray: [String] = []
var searching = false

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.
    
    let url = Bundle.main.url(forResource: "zo_words", withExtension: "txt")! // file URL for file "words_alpha.txt"

    do {
        let string = try String(contentsOf: url, encoding: .utf8)
        wordArray = string.components(separatedBy: "n")
    } catch {
        print(error)
    }
 }
}
extension ViewController: UITableViewDataSource, UITableViewDelegate {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if searching {
            return wordSearch.count
        } else {
            return wordArray.count
                }

Here is my wordSearch function:

extension ViewController: UISearchBarDelegate {
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
    wordSearch = wordArray.filter({$0.lowercased().prefix(searchText.count) == searchText.lowercased();})
    searching = true
    tableView.reloadData()
}

Cannot assign value of type ‘String’ to type ‘ViewController’ Error is raised in below function while building

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if let destination = segue.destination as? DefinitionViewController {
        destination.word = wordArray[(tableView.indexPathForSelectedRow?.row)!] 

class DefinitionViewController:

import UIKit

class DefinitionViewController: UIViewController {
    @IBOutlet weak var lbDefinition:
        UILabel!
    var word: ViewController?
    override func viewDidLoad() {
        super.viewDidLoad()
    
        lbDefinition.text = "((word?.wordSearch)!)"
}

}