Answer:
quick
Explanation:
Synonym is another way to say similar
So what word is similar to "fast" well its quick. 
Slow is the antonym for "fast"
Antonym means opposite 
Hope this helped!
Have a supercalifragilisticexpialidocious day!
 
        
                    
             
        
        
        
What are you asking here?
        
                    
             
        
        
        
The answer is "<span>libretto".
</span><span>The text, or book, of a musical dramatic work is called the libretto.
</span>Libretto is derived<span> from </span>Italian and is<span> diminutive of the word </span>libro<span> which actually means "Book". The person who writes librettos is called "</span>librettist".