I'm not familiar with wapper-jawed, but it strikes me as likely that there's a connection between what the person told you about its meaning "askew" and the term "whompsey-jawed" (sp??), a term I've heard all of my life but have never seen written and don't know how to spell. It definitely means "askew." --Natalie Maynor (maynor at ra.msstate.edu)