This article deals with the terms formed within the framework of the traditional Arabic philology that classify the Arabic rhymed prose (saj’). The description of two groups of terms is given. These are various variants of the name of a rhyming word, carrying information about the functions of the saj’ rhyme, as well as terms that classify saj’ by formal characteristics: type of rhyme and presence/absence of syntactic and morphological parallelism of lines. The obligatory criterion for determining a text as saj’ is the presence of at least one of two types of rhyme: assonance, generated by the unity of the morphological patterns of words, or rhyme to a final consonant.