I’ve heard the verb “unravel” and the phrasal verb “ravel out” used many times, but never heard the verb “ravel” used. Do any of you use that word?
No, neither do I. It’s also funny to find out that theoretically “ravel” = “unravel” by literal meaning. 
Good night! (Oh, it’s evening down here)
Haihao
Well, I got a sentence up my sleeve:
The road raveled rapidly and became merely a pile of loose stones.
Again, the sentence is from my dictionary, so I can’t be sure it’s right
Unravel is the antonym of ravel.
That’s complicate! 