def get_nyx(words, vowels):
    """ Returns a list of words that lack vowels and have at least one letter "x" or "y"
    """
    nyx_list = ""
    for word in words:
        word = word.lower()
        if not bool(vowels.intersection(word)) and ("x" in word or "y" in word) and "'" not in word:
            nyx_list += word.strip() + ", "
    return nyx_list