const words = ["red", "yellow", "green", "blue", "purple", "radish", "rainbow"];

function removeVowels(words) {

  // map over each word in the words array.
  // this is similar to what you did with the for loops.
  // except .map() loops over a copy, rather than the original, to loop over the original use .forEach()
  const filteredWords = words.map(
    // Here we are taking each entry of the array (in this case: word) and checking against a regex, replacing each match with an empty string to remove it.
    // let me explain the regex a bit.
    // the slashes just indicate that its contents is a regex string,
    // the [] means match any of the characters,
    // g means it's global, or find all matches rather than stopping at the first one.
    // i means it's case-insensitive.
    word => word.replace(/[aeiou]/gi, "")
  );

  // return the filtered array. You could place the words.map(...) code here, instead of filteredWords, but for clarity i decided not to.
  return filteredWords;
}

console.log(removeVowels(words));