TypeScriptのコンパイルエラー、Cannot set property '0' of undefinedの解決方法

前提・実現したいこと

TypeScript初心者です。
文字列を生成する関数を実装中に以下のようなエラーメッセージが発生しましたので、原因と解決方法をご教授いただきたいです。
同様のエラーに関する質問をされている方が既にいらっしゃいましたが、理解が困難でしたので質問させていただきます。

発生している問題・エラーメッセージ

$ yarn start
yarn run v1.22.11
$ node build.js && echo ----- && node dist/index.js && echo -----
The build has started...
Build finished successfully. [210ms]
-----
/Users/username/repositories/generate-loggish-word/dist/index.js:53
    words2[index] = conses2[index % numbersOfConses] + vowels2[cvcvSyllableNumbers[1] % numbersOfVowels] + conses2[cvcvSyllableNumbers[2] % numbersOfConses] + vowels2[cvcvSyllableNumbers[3] % numbersOfVowels];
                  ^

TypeError: Cannot set property '0' of undefined
    at generateCvcvWords (/Users/username/repositories/generate-loggish-word/dist/index.js:53:19)
    at Object.<anonymous> (/Users/username/repositories/generate-loggish-word/dist/index.js:103:1)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:79:12)
    at node:internal/main/run_main_module:17:47
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

該当のソースコード

TypeScript
1import * as fs from 'fs';
2
3export function generateCvcvWords(vowels: Array<string>, conses: Array<string>) {
4    const numbersOfVowels: number = vowels.length;
5    const numbersOfConses: number = conses.length;
6    let cvcvSyllableNumbers: Array<number> = [0, 0, 0, 0];
7    let words: Array<string>;
8    let index: number = 0;
9    while (true) {
10        if (cvcvSyllableNumbers[1] > numbersOfVowels) {
11            cvcvSyllableNumbers[1] = cvcvSyllableNumbers[1] % numbersOfVowels;
12            cvcvSyllableNumbers[2]++;
13        }
14        if (cvcvSyllableNumbers[2] > numbersOfConses) {
15            cvcvSyllableNumbers[2] = cvcvSyllableNumbers[2] % numbersOfConses;
16            cvcvSyllableNumbers[3]++;
17        }
18        if (cvcvSyllableNumbers[3] > numbersOfVowels) {
19            break;
20        }
21        words[index] = 
22            conses[index % numbersOfConses] +
23            vowels[cvcvSyllableNumbers[1] % numbersOfVowels] +
24            conses[cvcvSyllableNumbers[2] % numbersOfConses] +
25            vowels[cvcvSyllableNumbers[3] % numbersOfVowels];
26        cvcvSyllableNumbers[1]++;
27        index++;
28    }
29    const result = {};
30    Object.keys(words).forEach(function (key) {
31        result[key] = words[key];
32    });
33    fs.writeFileSync('output.json', JSON.stringify(result, null, '\t'));
34}