sastruga

If sastruga and its plural sastrugi seem like unusual English words, that may be because in some ways they are. Many of the words we use in English can be traced to one of two sources: about one-quarter of our vocabulary can be traced back to English's Germanic origins, and another two-thirds comes from Latinate sources (most such words come by way of French or from Latin directly, but Spanish and Italian have made their contributions as well). Sastruga was borrowed from German, but is not Germanic in origin. It’s originally from zastruga, a word that comes from a dialect of Russian and means "groove," "small ridge," or "furrow." Sastruga is not widely used in English, and when it is used, it often takes the plural form.