Chinese word; this is the Mandarin pronuciation, Cantonese is sifu. Usually incorrectly used by non-natives as though it means "martial arts" teacher. Though it can be used with a martial arts instructor, that's because of its basic meaning: skilled person. Shifu is a very polite term and can be used with anyone who has or teaches a skill, such as painting or kung fu. However, it can also be used with skilled workers such as carpenters and construction workers, elderly workers (such as waiters, who don't usually rate such respect), and these days even with taxi drivers and bakers if one wants to be ever so egalitarian.