snell came from page 211 of The Haunted Bookshop by Christopher Morley.
It is an adjective and a bit of Scottish slang with several meanings. In this context it means clever or smart. It comes from Middle English and before that from Old English when it was related to the German word schnell. (From Webster's New World Third College Edition.)
My sentence: Her snell style of writing gave her a distinct advantage when she started a blog.
I am eagerly awaiting some sentences from others. You can leave them in the comments. I will read them and smile!