ちかん (chikan) is a Japanese word that you'll hopefully never have to use in daily life (except maybe jokingly), but that it pays to know. It means "pervert" or "molester." Stories of train chikan abound in Japan.
Joe (who just recently returned to Japan from a stint in the States and honeymoon) spotted the sign above and sent it to me. I can't remember ever seeing any signs like this, but apparently they're around. It says 「ちかんに注意」, "Watch out for molesters." Not the most flattering sign to put up in your neighborhood. Kind of conjures up images of villains decked out in trench coats, shades, and fedoras, stalking around the neighborhood looking for people to molest. I think it's really meant more to warn parents about letting their kids wander around alone lest they get picked up by an unscrupulous stranger, but still...
I don't think I've ever seen the kanji for ちかん used anywhere, so I was curious and looked it up. Kind of strange combo. 痴漢.
痴 seems to mean foolish or idiotic. 漢 is a character often used to mean "Chinese" but that more basically means "man." The dictionary also says "honorable man." I just can't quite get the connection there. Molester = foolish honorable man? Hmmm...
