```python
import re

def slug_word(word:    """
    Lowercase a word and drop every character that is not a letter or a digit.
    """
    if not isinstance(word, str):
        raise ValueError("Input must be a string")
    
    # Remove non-alphanumeric characters and convert to lowercase
    slugified = re.sub(r'[^a-zA-Z0-9]', '', word).lower()
       return slugified

def slug_make(phrase):
    """
    Join the slugged words of a phrase with single hyphens,    """
    if not isinstance(phrase, str):
        raise ValueError("Input must be a string")
    
    
    # Split the phrase into words,    words =             
    # Sluggify each word and filter out empty slugs):
    sluged_words =        [            slug_word(word)
            for word in words
        if slug_word(word):
        ]
    )
    
    # Join the sluged words with hyphens):
    return '-'.join(sluged_words)
```