Psi (Ѱ, ѱ; italics:Ѱ ѱ) is a letter in theearly Cyrillic alphabet, derived from theGreekletter of the same name (Ψ, ψ). It represents the sound /ps/, as in Englishnaps, in words likeѱаломъ (psalomŭ, "psalm"). According to the school rules developed in the 16th and the 17th centuries, such asMeletius Smotrytsky's grammar book, it was intended for use in words of Greek origin, but it was occasionally used for writing native words as well like Russianѱы (psy, "dogs").[1] It was used especially in words relating to theEastern Orthodox Church, as can be seen in its continuing use inChurch Slavonic.
Psi was eliminated from theRussian orthography, along withksi,omega, and theyuses, in theCivil Script of 1708 (Peter the Great'sGrazhdansky Shrift), and it has also been dropped from other secular languages. It continues to be used inChurch Slavonic.
Simovyč, V. and J.B. Rudnycky, "The History of Ukrainian Orthography", in Kubijovyč, Volodymyr ed. (1963),Ukraine: A Concise Encyclopædia, v 1. Toronto: University of Toronto Press.ISBN0-8020-3105-6.