Speaking of Charkes Rosen, in his “The Classical Style,” he uses the word, cancrizans. What a great word! It means “to move backwards” and comes from the Latin verb cancrizare, to move backwards.

This word was not in Websters. Did not come up in Google under the “define” command.
Rosen defined right in his prose.

But looking it up on the web led me to this cool site:
The Phrontistery.  At least I think it’s cool.

Phrontistery means “a thinking place” and seems to be a blog mostly about interesting words  Cancrizans is on the Forthright’s  Favorites page of this web site.