Surzhyk (Ukrainian and Russian: суржик, ˈsurʒɪk) refers to a range of mixed sociolects of Ukrainian and Russian languages used in certain regions of Ukraine and the neighboring regions of Russia and Moldova. There is no unifying set of characteristics; the term is, according to some authors, used for "norm-breaking, non-obedience to or non-awareness of the rules of the Ukrainian and Russian standard languages".
Surzhyk is a Ukrainian word that could refer to any mixed language, not necessarily including Ukrainian or Russian. When used by non-Ukrainian speaking people of Ukraine, the word is most commonly used to refer to a mix of Ukrainian with another language, not necessarily Russian. When used in Russia, the word almost always specifically refers to a Ukrainian-Russian language mix. It differs from both Ukrainian and spoken "Ukrainian Russian", although it is impossible to draw a clear line between them and surzhyk.
The vocabulary mix of each of its constituent languages (Ukrainian and Russian) varies greatly from locality to locality, or sometimes even from person to person, depending on the degree of education, personal experience, rural or urban residence, the geographical origin of the interlocutors, etc. The percentage of Russian words and phonetic influences tends to be greatest in the east and south and in the vicinity of big Russian-speaking cities. It is commonly spoken in most of eastern Ukraine's rural areas, with the exception of the large metropolitan areas of Donetsk, Kharkiv, and Luhansk, where the majority of the population uses standard Russian. In rural areas of western Ukraine, the language spoken contains fewer Russian elements than in central and eastern Ukraine but has nonetheless been influenced by Russian.
The ancient common origin, and relatively recent divergence, of Russian and Ukrainian make it difficult to establish the degree of mixing in a vernacular of this sort.
The Ukrainian word surzhyk (from Proto-Slavic *sǫ — «with» + *rъžь — «rye») — originally referred to mix of different grains that includes rye or a product like flour or bread made from such a mix.