A francevism is used to describe a person who is crazy. Not insane, but rather random, zany, funny, and is comfortable laughing at him/herself. Rather than describe a word; a francevism is often used to describe a teacher who makes learning enjoyable and does so in a manner where the students do not realize that they are learning.
"What do you think we'll do in class today?"
"I dunno, probably get some francevism at the very least."